Chapter 6, Problem 2TP

To determine

To explain: When to use test-retest and parallel form reliability.

Answer to Problem 2TP

Test-retest reliability is used when same samples are checked for different time interval where as parallel form reliability is used when different samples are considered.

Explanation of Solution

Test-retest reliability:

The given test is used when same thing is tested over the different duration. This test assumes that there is no notable change in the data being measured between the two time slots. The amount of time in between is critical. More the time gap yield less value of correlation factor where as lesser the time gap more will be the value of correlation factor. Since correlation factor is only responsible for test-retest reliability.

Hence, for different time interval the correlation factor can be calculated.

For example if researcher wants to measure the reliability of two courses in the University for Different Time Slabs, he should use the concept of test retest reliability. As it will conclude how reliable the two courses are if the correlation factor is nearly same between the two time slab.

Parallel-form reliability:

Two different parallel forms. Two different samples are being taken. The correlation between the two forms concludes the reliability. Mostly the samples are random only divided.

It is developed so the samples must be individually and correctly measure.

For example if the study is related to the memorizing of 15 different general news and re reciting it after 20 min involves training of intellectual skills. So the same task is being performed in the different time slab but it is not same as far as content related to the same thoughts are being used in different form. Hence two parallel forms are being generated so the parallel form test will be applicable in such instances.

Test-retest reliability is used when same samples are checked for different time interval where as parallel form reliability is used when different samples are considered.