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Point Bicerial Correlation Coefficient

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Point Bicerial Correlation Coefficient

  1. 1. POINT BISERIAL CORRELATION COEFFICIENT Used to correlate a dichotomous variable with a continuous variable In testing, used to correlate a person’s performance on an item (correct, incorrect) with their total test score Used as an index of item discrimination
  2. 2. Point biserial correlation coefficient  denoted by rpb , is appropriate in measuring the correlation between a real nominal dichotomous variable and an interval or ratio variable.
  3. 3. Point-biserial formula Mean on the test for people who got item correct Mean on the test for Standard people who got item deviation incorrect for test IF for item 1 – IF for item
  4. 4. Scores 0f 20 Students in a Comprehensive Math Test STUDENT SEX(X) SCORE (Y) 1 1 15 2 0 21 3 0 16 4 1 17 5 0 18 6 0 14 7 0 32 8 1 22 9 0 23 10 1 20
  5. 5. STUDENT SEX (X) SCORE (Y) 11 0 18 12 1 26 13 0 25 14 0 28 15 1 29 16 1 26 17 0 34 18 1 30 19 1 35 20 0 29
  6. 6. ACTIVITY Scores 0f 20 Students in a Comprehensive Math Test STUDENT SEX(X) SCORE (Y) 1 1 13 2 0 16 3 0 17 4 1 20 5 0 22 6 0 38 7 0 25 8 1 32 9 0 23 10 1 19

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