Ordered Factors

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# Generate some fake data about education in 1000 observations
education <- c("some high school", "high school", "college", "masters", "phd")
obs <- sample(education, 1000, replace = TRUE)
obs
   [1] "college"          "college"          "college"         
   [4] "phd"              "high school"      "college"         
   [7] "phd"              "masters"          "high school"     
  [10] "some high school" "high school"      "masters"         
  [13] "high school"      "phd"              "some high school"
  [16] "masters"          "some high school" "high school"     
  [19] "phd"              "college"          "college"         
  [22] "phd"              "college"          "high school"     
  [25] "high school"      "college"          "high school"     
  [28] "college"          "college"          "high school"     
  [31] "high school"      "phd"              "some high school"
  [34] "some high school" "high school"      "high school"     
  [37] "phd"              "phd"              "college"         
  [40] "some high school" "masters"          "phd"             
  [43] "college"          "some high school" "phd"             
  [46] "phd"              "some high school" "high school"     
  [49] "high school"      "masters"          "some high school"
  [52] "masters"          "some high school" "masters"         
  [55] "high school"      "some high school" "some high school"
  [58] "masters"          "masters"          "masters"         
  [61] "phd"              "phd"              "some high school"
  [64] "masters"          "masters"          "high school"     
  [67] "college"          "college"          "phd"             
  [70] "some high school" "high school"      "college"         
  [73] "phd"              "phd"              "high school"     
  [76] "college"          "some high school" "phd"             
  [79] "college"          "phd"              "masters"         
  [82] "phd"              "masters"          "masters"         
  [85] "college"          "college"          "college"         
  [88] "high school"      "college"          "phd"             
  [91] "some high school" "high school"      "masters"         
  [94] "masters"          "phd"              "some high school"
  [97] "masters"          "phd"              "some high school"
 [100] "masters"          "some high school" "phd"             
 [103] "masters"          "masters"          "masters"         
 [106] "some high school" "high school"      "phd"             
 [109] "phd"              "some high school" "masters"         
 [112] "phd"              "phd"              "college"         
 [115] "masters"          "college"          "college"         
 [118] "college"          "college"          "some high school"
 [121] "phd"              "high school"      "high school"     
 [124] "high school"      "phd"              "phd"             
 [127] "college"          "high school"      "phd"             
 [130] "high school"      "phd"              "high school"     
 [133] "phd"              "phd"              "college"         
 [136] "high school"      "high school"      "high school"     
 [139] "masters"          "masters"          "phd"             
 [142] "masters"          "college"          "masters"         
 [145] "college"          "masters"          "phd"             
 [148] "high school"      "masters"          "phd"             
 [151] "masters"          "college"          "high school"     
 [154] "college"          "masters"          "some high school"
 [157] "college"          "college"          "phd"             
 [160] "high school"      "masters"          "phd"             
 [163] "masters"          "some high school" "college"         
 [166] "some high school" "high school"      "some high school"
 [169] "college"          "high school"      "phd"             
 [172] "masters"          "phd"              "some high school"
 [175] "some high school" "phd"              "phd"             
 [178] "masters"          "phd"              "college"         
 [181] "high school"      "some high school" "some high school"
 [184] "college"          "high school"      "high school"     
 [187] "phd"              "high school"      "masters"         
 [190] "some high school" "high school"      "masters"         
 [193] "high school"      "college"          "college"         
 [196] "masters"          "some high school" "masters"         
 [199] "some high school" "college"          "phd"             
 [202] "some high school" "college"          "high school"     
 [205] "phd"              "masters"          "phd"             
 [208] "college"          "some high school" "some high school"
 [211] "high school"      "some high school" "some high school"
 [214] "phd"              "masters"          "some high school"
 [217] "some high school" "college"          "masters"         
 [220] "college"          "masters"          "some high school"
 [223] "phd"              "phd"              "high school"     
 [226] "masters"          "college"          "some high school"
 [229] "phd"              "college"          "some high school"
 [232] "college"          "some high school" "phd"             
 [235] "high school"      "phd"              "masters"         
 [238] "high school"      "phd"              "masters"         
 [241] "high school"      "masters"          "masters"         
 [244] "masters"          "college"          "some high school"
 [247] "phd"              "masters"          "masters"         
 [250] "some high school" "phd"              "high school"     
 [253] "some high school" "some high school" "college"         
 [256] "some high school" "masters"          "high school"     
 [259] "high school"      "some high school" "high school"     
 [262] "high school"      "high school"      "phd"             
 [265] "masters"          "high school"      "college"         
 [268] "some high school" "masters"          "high school"     
 [271] "phd"              "some high school" "high school"     
 [274] "high school"      "masters"          "high school"     
 [277] "masters"          "phd"              "masters"         
 [280] "phd"              "phd"              "college"         
 [283] "masters"          "some high school" "masters"         
 [286] "phd"              "masters"          "college"         
 [289] "masters"          "high school"      "some high school"
 [292] "phd"              "phd"              "masters"         
 [295] "phd"              "high school"      "college"         
 [298] "masters"          "masters"          "masters"         
 [301] "phd"              "college"          "college"         
 [304] "phd"              "high school"      "masters"         
 [307] "high school"      "masters"          "some high school"
 [310] "college"          "phd"              "some high school"
 [313] "college"          "some high school" "college"         
 [316] "high school"      "masters"          "college"         
 [319] "masters"          "college"          "college"         
 [322] "college"          "masters"          "some high school"
 [325] "masters"          "masters"          "masters"         
 [328] "masters"          "masters"          "phd"             
 [331] "college"          "some high school" "some high school"
 [334] "masters"          "high school"      "high school"     
 [337] "some high school" "phd"              "masters"         
 [340] "some high school" "phd"              "some high school"
 [343] "masters"          "phd"              "college"         
 [346] "some high school" "phd"              "high school"     
 [349] "masters"          "college"          "college"         
 [352] "phd"              "masters"          "high school"     
 [355] "high school"      "high school"      "masters"         
 [358] "phd"              "phd"              "masters"         
 [361] "phd"              "masters"          "high school"     
 [364] "some high school" "college"          "high school"     
 [367] "some high school" "some high school" "phd"             
 [370] "some high school" "phd"              "phd"             
 [373] "some high school" "masters"          "high school"     
 [376] "college"          "masters"          "some high school"
 [379] "some high school" "some high school" "some high school"
 [382] "masters"          "phd"              "masters"         
 [385] "masters"          "high school"      "masters"         
 [388] "masters"          "college"          "phd"             
 [391] "high school"      "some high school" "masters"         
 [394] "masters"          "masters"          "masters"         
 [397] "college"          "phd"              "high school"     
 [400] "masters"          "high school"      "masters"         
 [403] "college"          "high school"      "some high school"
 [406] "phd"              "phd"              "masters"         
 [409] "phd"              "masters"          "masters"         
 [412] "phd"              "masters"          "high school"     
 [415] "college"          "masters"          "college"         
 [418] "masters"          "phd"              "phd"             
 [421] "college"          "college"          "some high school"
 [424] "masters"          "some high school" "phd"             
 [427] "college"          "masters"          "some high school"
 [430] "college"          "some high school" "college"         
 [433] "masters"          "masters"          "some high school"
 [436] "masters"          "high school"      "some high school"
 [439] "phd"              "phd"              "college"         
 [442] "phd"              "high school"      "some high school"
 [445] "some high school" "some high school" "phd"             
 [448] "high school"      "masters"          "masters"         
 [451] "some high school" "masters"          "some high school"
 [454] "college"          "masters"          "masters"         
 [457] "some high school" "phd"              "college"         
 [460] "masters"          "high school"      "some high school"
 [463] "some high school" "college"          "phd"             
 [466] "high school"      "masters"          "high school"     
 [469] "high school"      "some high school" "phd"             
 [472] "high school"      "some high school" "some high school"
 [475] "college"          "college"          "masters"         
 [478] "phd"              "masters"          "masters"         
 [481] "high school"      "high school"      "phd"             
 [484] "college"          "some high school" "phd"             
 [487] "masters"          "phd"              "some high school"
 [490] "high school"      "college"          "some high school"
 [493] "high school"      "phd"              "college"         
 [496] "phd"              "masters"          "phd"             
 [499] "some high school" "phd"              "high school"     
 [502] "phd"              "college"          "some high school"
 [505] "masters"          "phd"              "some high school"
 [508] "high school"      "phd"              "masters"         
 [511] "masters"          "some high school" "high school"     
 [514] "some high school" "masters"          "some high school"
 [517] "some high school" "phd"              "phd"             
 [520] "some high school" "phd"              "high school"     
 [523] "some high school" "masters"          "college"         
 [526] "high school"      "high school"      "phd"             
 [529] "high school"      "college"          "phd"             
 [532] "masters"          "high school"      "college"         
 [535] "masters"          "college"          "college"         
 [538] "college"          "some high school" "college"         
 [541] "phd"              "phd"              "college"         
 [544] "college"          "phd"              "college"         
 [547] "masters"          "college"          "masters"         
 [550] "phd"              "college"          "college"         
 [553] "college"          "some high school" "high school"     
 [556] "masters"          "phd"              "some high school"
 [559] "masters"          "masters"          "high school"     
 [562] "high school"      "phd"              "phd"             
 [565] "college"          "college"          "some high school"
 [568] "college"          "college"          "masters"         
 [571] "high school"      "phd"              "phd"             
 [574] "phd"              "masters"          "some high school"
 [577] "college"          "masters"          "college"         
 [580] "phd"              "masters"          "college"         
 [583] "college"          "phd"              "phd"             
 [586] "some high school" "phd"              "college"         
 [589] "high school"      "phd"              "some high school"
 [592] "masters"          "masters"          "masters"         
 [595] "college"          "masters"          "college"         
 [598] "college"          "college"          "high school"     
 [601] "masters"          "masters"          "phd"             
 [604] "phd"              "phd"              "college"         
 [607] "college"          "phd"              "phd"             
 [610] "phd"              "college"          "college"         
 [613] "masters"          "phd"              "masters"         
 [616] "high school"      "phd"              "college"         
 [619] "masters"          "high school"      "masters"         
 [622] "masters"          "masters"          "college"         
 [625] "phd"              "phd"              "masters"         
 [628] "some high school" "college"          "masters"         
 [631] "masters"          "college"          "high school"     
 [634] "some high school" "college"          "college"         
 [637] "college"          "phd"              "college"         
 [640] "masters"          "college"          "some high school"
 [643] "some high school" "phd"              "high school"     
 [646] "masters"          "college"          "high school"     
 [649] "high school"      "college"          "some high school"
 [652] "high school"      "phd"              "high school"     
 [655] "masters"          "masters"          "high school"     
 [658] "high school"      "some high school" "masters"         
 [661] "phd"              "high school"      "phd"             
 [664] "masters"          "masters"          "high school"     
 [667] "high school"      "masters"          "masters"         
 [670] "college"          "phd"              "some high school"
 [673] "masters"          "phd"              "some high school"
 [676] "high school"      "college"          "some high school"
 [679] "some high school" "high school"      "phd"             
 [682] "phd"              "college"          "phd"             
 [685] "some high school" "masters"          "high school"     
 [688] "college"          "masters"          "college"         
 [691] "college"          "masters"          "some high school"
 [694] "some high school" "college"          "some high school"
 [697] "high school"      "high school"      "phd"             
 [700] "some high school" "masters"          "phd"             
 [703] "high school"      "some high school" "college"         
 [706] "college"          "college"          "college"         
 [709] "some high school" "college"          "college"         
 [712] "some high school" "college"          "masters"         
 [715] "phd"              "college"          "phd"             
 [718] "high school"      "college"          "masters"         
 [721] "phd"              "some high school" "some high school"
 [724] "some high school" "masters"          "college"         
 [727] "college"          "some high school" "college"         
 [730] "masters"          "masters"          "high school"     
 [733] "phd"              "phd"              "college"         
 [736] "phd"              "college"          "college"         
 [739] "masters"          "some high school" "masters"         
 [742] "masters"          "high school"      "some high school"
 [745] "high school"      "phd"              "high school"     
 [748] "some high school" "masters"          "high school"     
 [751] "some high school" "phd"              "phd"             
 [754] "high school"      "college"          "high school"     
 [757] "college"          "college"          "masters"         
 [760] "phd"              "masters"          "phd"             
 [763] "high school"      "high school"      "high school"     
 [766] "college"          "masters"          "some high school"
 [769] "high school"      "phd"              "some high school"
 [772] "masters"          "some high school" "masters"         
 [775] "phd"              "some high school" "some high school"
 [778] "masters"          "high school"      "phd"             
 [781] "phd"              "some high school" "college"         
 [784] "some high school" "phd"              "some high school"
 [787] "masters"          "masters"          "masters"         
 [790] "college"          "high school"      "phd"             
 [793] "high school"      "college"          "some high school"
 [796] "high school"      "masters"          "phd"             
 [799] "college"          "some high school" "high school"     
 [802] "phd"              "college"          "high school"     
 [805] "masters"          "some high school" "college"         
 [808] "some high school" "high school"      "phd"             
 [811] "high school"      "high school"      "masters"         
 [814] "some high school" "some high school" "phd"             
 [817] "masters"          "college"          "high school"     
 [820] "masters"          "college"          "some high school"
 [823] "high school"      "high school"      "phd"             
 [826] "college"          "college"          "college"         
 [829] "college"          "masters"          "masters"         
 [832] "high school"      "some high school" "phd"             
 [835] "college"          "some high school" "some high school"
 [838] "high school"      "high school"      "college"         
 [841] "phd"              "high school"      "college"         
 [844] "phd"              "high school"      "college"         
 [847] "masters"          "college"          "college"         
 [850] "some high school" "some high school" "high school"     
 [853] "high school"      "high school"      "high school"     
 [856] "masters"          "high school"      "high school"     
 [859] "phd"              "some high school" "phd"             
 [862] "college"          "some high school" "college"         
 [865] "masters"          "phd"              "college"         
 [868] "phd"              "phd"              "some high school"
 [871] "high school"      "masters"          "some high school"
 [874] "masters"          "college"          "high school"     
 [877] "phd"              "high school"      "masters"         
 [880] "masters"          "some high school" "college"         
 [883] "some high school" "college"          "masters"         
 [886] "college"          "college"          "some high school"
 [889] "phd"              "phd"              "college"         
 [892] "phd"              "phd"              "masters"         
 [895] "college"          "phd"              "masters"         
 [898] "some high school" "high school"      "college"         
 [901] "high school"      "college"          "some high school"
 [904] "high school"      "masters"          "college"         
 [907] "masters"          "college"          "college"         
 [910] "some high school" "college"          "some high school"
 [913] "masters"          "phd"              "high school"     
 [916] "college"          "some high school" "phd"             
 [919] "high school"      "masters"          "some high school"
 [922] "phd"              "high school"      "some high school"
 [925] "phd"              "high school"      "phd"             
 [928] "high school"      "some high school" "some high school"
 [931] "high school"      "phd"              "masters"         
 [934] "some high school" "high school"      "some high school"
 [937] "phd"              "masters"          "high school"     
 [940] "college"          "some high school" "some high school"
 [943] "masters"          "some high school" "phd"             
 [946] "some high school" "phd"              "some high school"
 [949] "college"          "phd"              "phd"             
 [952] "masters"          "college"          "high school"     
 [955] "high school"      "masters"          "phd"             
 [958] "high school"      "phd"              "college"         
 [961] "masters"          "masters"          "phd"             
 [964] "college"          "masters"          "college"         
 [967] "college"          "some high school" "phd"             
 [970] "college"          "some high school" "some high school"
 [973] "high school"      "masters"          "some high school"
 [976] "phd"              "college"          "high school"     
 [979] "phd"              "high school"      "high school"     
 [982] "phd"              "masters"          "masters"         
 [985] "some high school" "high school"      "phd"             
 [988] "phd"              "college"          "phd"             
 [991] "college"          "high school"      "some high school"
 [994] "some high school" "college"          "some high school"
 [997] "high school"      "masters"          "masters"         
[1000] "phd"
# Turn the same into a ordered factor
obs.ordered <- ordered(obs)
obs.ordered
   [1] college          college          college          phd             
   [5] high school      college          phd              masters         
   [9] high school      some high school high school      masters         
  [13] high school      phd              some high school masters         
  [17] some high school high school      phd              college         
  [21] college          phd              college          high school     
  [25] high school      college          high school      college         
  [29] college          high school      high school      phd             
  [33] some high school some high school high school      high school     
  [37] phd              phd              college          some high school
  [41] masters          phd              college          some high school
  [45] phd              phd              some high school high school     
  [49] high school      masters          some high school masters         
  [53] some high school masters          high school      some high school
  [57] some high school masters          masters          masters         
  [61] phd              phd              some high school masters         
  [65] masters          high school      college          college         
  [69] phd              some high school high school      college         
  [73] phd              phd              high school      college         
  [77] some high school phd              college          phd             
  [81] masters          phd              masters          masters         
  [85] college          college          college          high school     
  [89] college          phd              some high school high school     
  [93] masters          masters          phd              some high school
  [97] masters          phd              some high school masters         
 [101] some high school phd              masters          masters         
 [105] masters          some high school high school      phd             
 [109] phd              some high school masters          phd             
 [113] phd              college          masters          college         
 [117] college          college          college          some high school
 [121] phd              high school      high school      high school     
 [125] phd              phd              college          high school     
 [129] phd              high school      phd              high school     
 [133] phd              phd              college          high school     
 [137] high school      high school      masters          masters         
 [141] phd              masters          college          masters         
 [145] college          masters          phd              high school     
 [149] masters          phd              masters          college         
 [153] high school      college          masters          some high school
 [157] college          college          phd              high school     
 [161] masters          phd              masters          some high school
 [165] college          some high school high school      some high school
 [169] college          high school      phd              masters         
 [173] phd              some high school some high school phd             
 [177] phd              masters          phd              college         
 [181] high school      some high school some high school college         
 [185] high school      high school      phd              high school     
 [189] masters          some high school high school      masters         
 [193] high school      college          college          masters         
 [197] some high school masters          some high school college         
 [201] phd              some high school college          high school     
 [205] phd              masters          phd              college         
 [209] some high school some high school high school      some high school
 [213] some high school phd              masters          some high school
 [217] some high school college          masters          college         
 [221] masters          some high school phd              phd             
 [225] high school      masters          college          some high school
 [229] phd              college          some high school college         
 [233] some high school phd              high school      phd             
 [237] masters          high school      phd              masters         
 [241] high school      masters          masters          masters         
 [245] college          some high school phd              masters         
 [249] masters          some high school phd              high school     
 [253] some high school some high school college          some high school
 [257] masters          high school      high school      some high school
 [261] high school      high school      high school      phd             
 [265] masters          high school      college          some high school
 [269] masters          high school      phd              some high school
 [273] high school      high school      masters          high school     
 [277] masters          phd              masters          phd             
 [281] phd              college          masters          some high school
 [285] masters          phd              masters          college         
 [289] masters          high school      some high school phd             
 [293] phd              masters          phd              high school     
 [297] college          masters          masters          masters         
 [301] phd              college          college          phd             
 [305] high school      masters          high school      masters         
 [309] some high school college          phd              some high school
 [313] college          some high school college          high school     
 [317] masters          college          masters          college         
 [321] college          college          masters          some high school
 [325] masters          masters          masters          masters         
 [329] masters          phd              college          some high school
 [333] some high school masters          high school      high school     
 [337] some high school phd              masters          some high school
 [341] phd              some high school masters          phd             
 [345] college          some high school phd              high school     
 [349] masters          college          college          phd             
 [353] masters          high school      high school      high school     
 [357] masters          phd              phd              masters         
 [361] phd              masters          high school      some high school
 [365] college          high school      some high school some high school
 [369] phd              some high school phd              phd             
 [373] some high school masters          high school      college         
 [377] masters          some high school some high school some high school
 [381] some high school masters          phd              masters         
 [385] masters          high school      masters          masters         
 [389] college          phd              high school      some high school
 [393] masters          masters          masters          masters         
 [397] college          phd              high school      masters         
 [401] high school      masters          college          high school     
 [405] some high school phd              phd              masters         
 [409] phd              masters          masters          phd             
 [413] masters          high school      college          masters         
 [417] college          masters          phd              phd             
 [421] college          college          some high school masters         
 [425] some high school phd              college          masters         
 [429] some high school college          some high school college         
 [433] masters          masters          some high school masters         
 [437] high school      some high school phd              phd             
 [441] college          phd              high school      some high school
 [445] some high school some high school phd              high school     
 [449] masters          masters          some high school masters         
 [453] some high school college          masters          masters         
 [457] some high school phd              college          masters         
 [461] high school      some high school some high school college         
 [465] phd              high school      masters          high school     
 [469] high school      some high school phd              high school     
 [473] some high school some high school college          college         
 [477] masters          phd              masters          masters         
 [481] high school      high school      phd              college         
 [485] some high school phd              masters          phd             
 [489] some high school high school      college          some high school
 [493] high school      phd              college          phd             
 [497] masters          phd              some high school phd             
 [501] high school      phd              college          some high school
 [505] masters          phd              some high school high school     
 [509] phd              masters          masters          some high school
 [513] high school      some high school masters          some high school
 [517] some high school phd              phd              some high school
 [521] phd              high school      some high school masters         
 [525] college          high school      high school      phd             
 [529] high school      college          phd              masters         
 [533] high school      college          masters          college         
 [537] college          college          some high school college         
 [541] phd              phd              college          college         
 [545] phd              college          masters          college         
 [549] masters          phd              college          college         
 [553] college          some high school high school      masters         
 [557] phd              some high school masters          masters         
 [561] high school      high school      phd              phd             
 [565] college          college          some high school college         
 [569] college          masters          high school      phd             
 [573] phd              phd              masters          some high school
 [577] college          masters          college          phd             
 [581] masters          college          college          phd             
 [585] phd              some high school phd              college         
 [589] high school      phd              some high school masters         
 [593] masters          masters          college          masters         
 [597] college          college          college          high school     
 [601] masters          masters          phd              phd             
 [605] phd              college          college          phd             
 [609] phd              phd              college          college         
 [613] masters          phd              masters          high school     
 [617] phd              college          masters          high school     
 [621] masters          masters          masters          college         
 [625] phd              phd              masters          some high school
 [629] college          masters          masters          college         
 [633] high school      some high school college          college         
 [637] college          phd              college          masters         
 [641] college          some high school some high school phd             
 [645] high school      masters          college          high school     
 [649] high school      college          some high school high school     
 [653] phd              high school      masters          masters         
 [657] high school      high school      some high school masters         
 [661] phd              high school      phd              masters         
 [665] masters          high school      high school      masters         
 [669] masters          college          phd              some high school
 [673] masters          phd              some high school high school     
 [677] college          some high school some high school high school     
 [681] phd              phd              college          phd             
 [685] some high school masters          high school      college         
 [689] masters          college          college          masters         
 [693] some high school some high school college          some high school
 [697] high school      high school      phd              some high school
 [701] masters          phd              high school      some high school
 [705] college          college          college          college         
 [709] some high school college          college          some high school
 [713] college          masters          phd              college         
 [717] phd              high school      college          masters         
 [721] phd              some high school some high school some high school
 [725] masters          college          college          some high school
 [729] college          masters          masters          high school     
 [733] phd              phd              college          phd             
 [737] college          college          masters          some high school
 [741] masters          masters          high school      some high school
 [745] high school      phd              high school      some high school
 [749] masters          high school      some high school phd             
 [753] phd              high school      college          high school     
 [757] college          college          masters          phd             
 [761] masters          phd              high school      high school     
 [765] high school      college          masters          some high school
 [769] high school      phd              some high school masters         
 [773] some high school masters          phd              some high school
 [777] some high school masters          high school      phd             
 [781] phd              some high school college          some high school
 [785] phd              some high school masters          masters         
 [789] masters          college          high school      phd             
 [793] high school      college          some high school high school     
 [797] masters          phd              college          some high school
 [801] high school      phd              college          high school     
 [805] masters          some high school college          some high school
 [809] high school      phd              high school      high school     
 [813] masters          some high school some high school phd             
 [817] masters          college          high school      masters         
 [821] college          some high school high school      high school     
 [825] phd              college          college          college         
 [829] college          masters          masters          high school     
 [833] some high school phd              college          some high school
 [837] some high school high school      high school      college         
 [841] phd              high school      college          phd             
 [845] high school      college          masters          college         
 [849] college          some high school some high school high school     
 [853] high school      high school      high school      masters         
 [857] high school      high school      phd              some high school
 [861] phd              college          some high school college         
 [865] masters          phd              college          phd             
 [869] phd              some high school high school      masters         
 [873] some high school masters          college          high school     
 [877] phd              high school      masters          masters         
 [881] some high school college          some high school college         
 [885] masters          college          college          some high school
 [889] phd              phd              college          phd             
 [893] phd              masters          college          phd             
 [897] masters          some high school high school      college         
 [901] high school      college          some high school high school     
 [905] masters          college          masters          college         
 [909] college          some high school college          some high school
 [913] masters          phd              high school      college         
 [917] some high school phd              high school      masters         
 [921] some high school phd              high school      some high school
 [925] phd              high school      phd              high school     
 [929] some high school some high school high school      phd             
 [933] masters          some high school high school      some high school
 [937] phd              masters          high school      college         
 [941] some high school some high school masters          some high school
 [945] phd              some high school phd              some high school
 [949] college          phd              phd              masters         
 [953] college          high school      high school      masters         
 [957] phd              high school      phd              college         
 [961] masters          masters          phd              college         
 [965] masters          college          college          some high school
 [969] phd              college          some high school some high school
 [973] high school      masters          some high school phd             
 [977] college          high school      phd              high school     
 [981] high school      phd              masters          masters         
 [985] some high school high school      phd              phd             
 [989] college          phd              college          high school     
 [993] some high school some high school college          some high school
 [997] high school      masters          masters          phd             
Levels: college < high school < masters < phd < some high school