High School Grade Inflation: 1991 to 2003

Following up on a recent post on college grade inflation, there's also evidence that grade inflation is taking place at America's high schools.  In a study by the college entrance exam company ACT, it found evidence of significant grade inflation between 1991 and 2003 for high school students taking the ACT exam.  While ACT scores remained stable between 1991 and 2003, the chart above shows that the average high school GPA increased for every ACT composite score over that period.  From the study:

"Each point on each curve represents the average GPA for all students in 1991 and 2003 who earned that specific ACT Composite score.  The curve for 2003 is higher at every Composite score point than the 1991 curve, which is evidence of the existence of grade inflation.

However, the amount of grade inflation varies for different Composite score values: it is highest between the scores of 13 and 27 and steadily lower with Composite scores above 27. This is because students with high ACT Composite scores tend to have higher GPAs, and there is less room for these GPAs to increase over time because GPA cannot exceed 4.00. The average amount of grade inflation is about 0.25, or about one-quarter of one grade point on a grading scale with a range of 4 points (0.00 to 4.00). This means that, during the 13-year period under study, high school GPA for ACT-tested public high school graduates increased by about 6.25%—without an accompanying increase in ACT Composite score.

But this may understate the average amount of grade inflation when we consider that far fewer Ds and Fs are given in high school than As, Bs, or Cs. Data for the 13 years of this study show that the percentage of students with GPAs below 2.00 is less than 5 percent. This suggests that the practical range of high school grades is 2.00 (C) to 4.00 (A). So, with half of the possible grade range effectively eliminated from consideration, one-quarter of a grade point now represents not 6.25 but 12.5% of the range. Therefore, it may be more accurate to conclude that high school grades have inflated 12.5% between 1991 and 2003.

Conclusion: Due to grade inflation and other subjective factors, postsecondary institutions cannot be certain that high school grades always accurately depict the abilities of their applicants and entering first-year students. Because of this, they may find it difficult to make admissions decisions or course placement decisions with a sufficient level of confidence based  on high school GPA alone."

HT: Mike Donahue