Psychometric Calculator:

          What to Consider Before Conducting A Study


Before conducting a study, there are many important considerations to make.

Your ability to draw conclusions from data is limited by several factors such as reliability, validity, power, etc.

Click on one of the headings below to answer the relevant pre-analysis question.


[+] What is the reliability of my scale/test?


[+] How much more reliable will your scale/test will be if you lengthened/shortened it?


[+] How much longer/shorter does your scale/test need be for a desired reliabilty?


[+] What would the effect size between X and Y be if you took into account the unreliability of the measures?


[+] How big of an effect size can you find with your measures?


[+] How big of a(n) effect/sample size/type II error rate is needed to obtain a significant effect?


[+] How many studies will end up detecting an effect?


[+] How confident can I be in my effect size?


[+] What sample size do I need for a replication study?


[+] What percent of research findings are true?