1. R. E. Wyllys Copyright 2003 by R. E. Wyllys Last revised 2003 Jan 15
LIS Introduction to Research in Library and Information Science Choosing an Appropriate Statistical Test Procedure
R. E. Wyllys
Copyright 2003 by R. E. Wyllys
Last revised 2003 Jan 15
School of Information - The University of Texas at Austin
LIS 397.1, Introduction to Research in Library and Information Science

2. How to Choose a Standardized Statistical Test
Choice depends on your real-life problem
Figure out how many variables are involved
If just one variable, decide how many populations (groups) are involved
If two variables, consider nature of variables: interval or categorical
School of Information - The University of Texas at Austin
LIS 397.1, Introduction to Research in Library and Information Science

3. How to Choose a Standardized Statistical Test
1-Variable Problems: Is your question:
Does the variable have a particular mean value in some population? Use
Confidence interval
Does the variable average the same (i.e., does it have the same mean) in two populations? Use either
t-Test for dependent samples (if pairs of observations can be made on each element of your sample); else, t-Test for independent samples; or
ANOVA with repeated values (if paired observations can be made); else, ANOVA without repeated values
School of Information - The University of Texas at Austin
LIS 397.1, Introduction to Research in Library and Information Science

4. How to Choose a Standardized Statistical Test
2-Variable Problems: Is your question:
Is there some correlation or association between the variables? Use
Pearson correlation if variables are interval type
Chi-square test of association if variables are categorical type
Is it possible to estimate (predict) the value of one of a pair of interval variables on the basis of observing the value of the other? Use
Linear regression
School of Information - The University of Texas at Austin
LIS 397.1, Introduction to Research in Library and Information Science

5. After You Choose a Standardized Statistical Test
Choose the level of significance (or the confidence level) at which you want to work
Make your observations and enter them into an appropriate computer program
Using the program, apply your chosen test to your data
Note the resulting values of your test statistic and the probability or significance that the program reports for the test statistic
Accept or reject the null hypothesis that is built into the procedure you have used.
Interpret your decision with respect to your real-world problem
School of Information - The University of Texas at Austin
LIS 397.1, Introduction to Research in Library and Information Science

6. Statistics and Statistical Tests Can Be Valuable Tools in Solving Problems
School of Information - The University of Texas at Austin
LIS 397.1, Introduction to Research in Library and Information Science