Statistical Information
Planning for the IA

Calculating Standard Deviation:

Calculating t-calc: *remember when looking at a t-table, you must use a 2 tailed t-test; degrees of freedom = n-1 for each list of numbers (e.g. if you have a control group with 15 and a exp. group with 15 your df = 28)
The t(calc) must be = or > the t (critical) to show significance. Negative t's are showing directional, thus to determine if your value is significant you will use the absolute value of t.
t-table
How to report your t-test results:
(http://statistics-help-for-students.com/How_do_I_report_independent_samples_T_test_data_in_APA_style.htm#.WLBOF_LF7uE)


1. Test type and use


You want to tell your reader what type of analysis you conducted. If you don’t, your results won’t make much sense to the reader. You also want to tell your reader why this particular analysis was used. What did your analysis tests for?

Example


You can report data from your own experiments by using the template below.

“An independent-samples t-test was conducted to compare (your DV measure) _ in (IV level / condition 1) and (IV level / condition 2) conditions.”

If we were reporting data for our example, we might write a sentence like this.

“An independent-samples t-test was conducted to compare memory for words in sugar and no sugar conditions.”

2. Significant differences between conditions


You want to tell your reader whether or not there was a significant difference between condition means. You can report data from your own experiments by using the template below.

“There was a significant (not a significant) difference in the scores for IV level 1 (M=_, SD=_) and IV level 2 (M=_, SD=_) conditions; t(insert your df in this parentheses)=, p = __”