There is a big difference between an achievement test (e.g., end of the year standardized test, CTP, CPAA, Regents, NYC ELA exam, NYC Mathematics exam) and an admission test (e.g., ISEE, SSAT, SAT, ACT). The goal of an achievement test is to provide information about how well previously learned academic concepts have been mastered and retained, whereas the goal of an admissions test is to compare the performance of multiple students and to predict which students will be the most successful in academia.
In school, children are taught how to tackle achievement tests—how to memorize and understand information, recall it, and apply it on an exam. But children are not taught how to tackle admission tests. When preparing students for an ISEE or an SSAT, it is very important to have them look at concepts from a variety of angles and to train them to think “outside of the box” to discover ways to arrive at a correct answer. For instance, an achievement test will present material as follows:
If Tammy scored an 80%, 90%, and 100% on her first three exams, what is her mean and her range?
80 + 90 + 100 = 270/3 = 90
100 – 80 = 20
90% is her mean and 20 is her range
An admission test will test the same concepts, i.e. mean and range (measures of central tendency*), but in a much more challenging way. For example:
If Tammy took three tests that resulted in an average of 90%, and then five percentage points were added to each of her three exams, which measure of central tendency would change the least?
a)mean
b)median
c)mode
d)range
Since the students aren’t aren’t given the test grades, they can assume that Tammy scored a 90%, 90%, and 90% on her three tests (or any other combination of three numbers that average out to 90%). After making that assumption, students can calculate a mean of 90%, a median of 90%, a mode of 90% and a range of 0 (90-90 = 0). When five percentage points are added to each score, Tammy’s grades become a 95%, 95% and 95%. With these new grades, the mean becomes 95%, the median becomes 95%, the mode becomes 95%, and the range remains at 0 (95 – 95 = 0) . This means that all of the measures of central tendency increase by five percentage points except for the range, which stays the same. The answer is D.
As you can see, children need to be taught how to apply their knowledge to more challenging-type questions to succeed on an admissions test. Practice doesn’t make perfect, but it increases the likelihood of success.
*A measure of central tendency is a value that attempts to summarize a set of data such as mean, median, mode, range, etc. It is a commonly seen word on the quantitative section of the ISEE exam.
