Percent correct for 41 repeated questions
gainscore <- (percent_Correct_WN2018 - percent_Correct_OG) / (1 - percent_Correct_OG)
numeratorError <- sqrt(stdError_pCorrect_WN2018^2 + stdError_pCorrect_OG^2)
denominatorError <- stdError_pCorrect_OG
stdError_gainscore <- gainscore * sqrt((numeratorError/(percent_Correct_WN2018 - percent_Correct_OG))^2 + (denominatorError/(1- percent_Correct_OG))^2)
| 1 |
0.7536232 |
0.0173840 |
0.6293605 |
0.0185487 |
0.3352657 |
0.0706109 |
| 2 |
0.6988728 |
0.0183605 |
0.6540698 |
0.0178806 |
0.1295146 |
0.0743879 |
| 3 |
0.8599034 |
0.0139503 |
0.7593496 |
0.0170489 |
0.4178418 |
0.0962068 |
| 4 |
0.7777778 |
0.0167120 |
0.8430233 |
0.0136843 |
-0.4156379 |
-0.1422891 |
| 5 |
0.7842190 |
0.0165504 |
0.7863372 |
0.0158022 |
-0.0099138 |
-0.1071004 |
| 6 |
0.7262480 |
0.0178672 |
0.6325203 |
0.0197036 |
0.2550554 |
0.0736609 |
| 7 |
0.8421900 |
0.0146815 |
0.7593496 |
0.0172756 |
0.3442355 |
0.0973958 |
| 8 |
0.8792271 |
0.0129858 |
0.8016260 |
0.0158012 |
0.3911856 |
0.1077070 |
| 9 |
0.8325282 |
0.0148626 |
0.8629032 |
0.0136076 |
-0.2215592 |
-0.1486201 |
| 10 |
0.6537842 |
0.0191538 |
0.7281977 |
0.0170181 |
-0.2737778 |
-0.0958127 |
| 11 |
0.5169082 |
0.0199846 |
0.6191860 |
0.0184753 |
-0.2685769 |
-0.0726466 |
| 12 |
0.5362319 |
0.0198969 |
0.6243902 |
0.0193546 |
-0.2347073 |
-0.0748833 |
| 13 |
0.7929374 |
0.0163498 |
0.7777778 |
0.0167529 |
0.0682183 |
0.1054655 |
| 14 |
0.8170144 |
0.0154059 |
0.7503650 |
0.0164895 |
0.2669877 |
0.0921021 |
| 15 |
0.5345104 |
0.0200143 |
0.4850575 |
0.0235897 |
0.0960359 |
0.0602377 |
| 16 |
0.6869984 |
0.0184026 |
0.7335474 |
0.0176692 |
-0.1746988 |
-0.0964449 |
| 17 |
0.7415730 |
0.0175803 |
0.6094771 |
0.0194638 |
0.3382540 |
0.0692446 |
| 18 |
0.7174960 |
0.0179636 |
0.6091954 |
0.0233588 |
0.2771221 |
0.0771998 |
| 19 |
0.6099518 |
0.0193156 |
0.7007299 |
0.0174362 |
-0.3033316 |
-0.0887274 |
| 20 |
0.3772071 |
0.0194575 |
0.2896552 |
0.0218252 |
0.1232527 |
0.0413359 |
| 21 |
0.4991974 |
0.0198657 |
0.4656934 |
0.0188519 |
0.0627056 |
0.0513046 |
| 22 |
0.7445483 |
0.0170680 |
0.6847978 |
0.0172037 |
0.1895625 |
0.0775770 |
| 23 |
0.9065421 |
0.0115402 |
0.7622821 |
0.0168798 |
0.6068536 |
0.0962063 |
| 24 |
0.8068536 |
0.0156074 |
0.7291982 |
0.0172659 |
0.2867610 |
0.0878699 |
| 25 |
0.8333333 |
0.0146430 |
0.6717095 |
0.0182739 |
0.4923195 |
0.0764130 |
| 26 |
0.9065421 |
0.0114313 |
0.8284519 |
0.0139710 |
0.4552086 |
0.1115675 |
| 27 |
0.7274143 |
0.0174120 |
0.6652720 |
0.0177245 |
0.1856503 |
0.0748763 |
| 28 |
0.7056075 |
0.0180413 |
0.8730823 |
0.0124486 |
-1.3195543 |
-0.2158200 |
| 29 |
0.5342679 |
0.0198044 |
0.5975794 |
0.0190430 |
-0.1573267 |
-0.0686779 |
| 30 |
0.6417445 |
0.0188064 |
0.7726639 |
0.0154090 |
-0.5758844 |
-0.1138475 |
| 31 |
0.6137072 |
0.0193149 |
0.5198098 |
0.0198215 |
0.1955420 |
0.0581979 |
| 32 |
0.7939394 |
0.0157079 |
0.7756410 |
0.0166752 |
0.0815584 |
0.1022860 |
| 33 |
0.8060606 |
0.0156056 |
0.8451613 |
0.0145019 |
-0.2525253 |
-0.1396035 |
| 34 |
0.8000000 |
0.0155755 |
0.5076709 |
0.0185322 |
0.5937677 |
0.0540122 |
| 35 |
0.6863636 |
0.0180278 |
0.7319277 |
0.0172872 |
-0.1699694 |
-0.0938149 |
| 36 |
0.7833333 |
0.0162359 |
0.7790323 |
0.0167413 |
0.0194647 |
0.1055513 |
| 37 |
0.7863636 |
0.0160144 |
0.8019526 |
0.0149393 |
-0.0787132 |
-0.1107428 |
| 38 |
0.7287879 |
0.0173731 |
0.6971154 |
0.0184757 |
0.1045695 |
0.0839739 |
| 39 |
0.9015152 |
0.0114678 |
0.6069731 |
0.0197105 |
0.7494196 |
0.0691301 |
| 40 |
0.6000000 |
0.0191936 |
0.6080893 |
0.0183997 |
-0.0206406 |
-0.0678498 |
| 41 |
0.8000000 |
0.0155551 |
0.7515060 |
0.0169561 |
0.1951515 |
0.0935513 |
ggplot(percentCorrect_WN2018_OG) +
geom_point(aes(Number, `Gain Score`)) +
geom_errorbar(aes(Number, ymin = `Gain Score` - `Standard Error Gain Score`,
ymax = `Gain Score` + `Standard Error Gain Score`)) +
geom_hline(yintercept = 0, color = c("#56B4E9"))

ggplot(percentCorrect_WN2018_OG) +
geom_histogram(aes(`Gain Score`),
fill = c("#009E73"), alpha = .7, binwidth = .1) +
geom_vline(xintercept = 0, linetype = "longdash", alpha = .6) + geom_vline(xintercept = mean(percentCorrect_WN2018_OG$`Gain Score`), linetype = "dashed", color = c("#CC79A7"))

Reordered plot by order of questions as they appear in Winter 2018 exams.
All exams were combined, so if there are two exams with the same question number, the earlier exam would be placed first. Example: Exams 1, 3, and 4 all had a repeated question for their 5th question. So they are plotted in the order E1_Q5, E3_Q5, E4_Q5.
