Critical Thinking Personality Research and Stats

Ep 168: Reliability – the Foundation of Any Good Test

The Importance of Reliability in Personality Test

In this episode, as human curiosity drives us to self-discovery, we delve into personality tests’ reliability. Our innate curiosity pushes us to understand the very essence of who we are. This profound journey to self-discovery has led to the rise of personality tests, tools that profess to shine a light on the deepest corners of our psyche. However, the pivotal question arises: How can we trust these tools? The answer lies in the reliability of such tests.


Understanding Reliability

Reliability, in the context of psychology and testing, refers to the consistency of a test. A reliable test will provide similar results under consistent conditions, ensuring that the insights gained from these tests remain trustworthy over repeated applications.

A Deep Dive into Types of Test Reliability

Test-Retest Reliability:

Imagine revisiting an ice cream parlor multiple times, each time expecting the same flavor profile from your chosen flavor. If the taste changes each visit, you’d begin to doubt the consistency of the product. In much the same vein, if a personality test provides vastly different results when taken multiple times by the same individual under the same conditions, its reliability is questionable.

Split-Half Reliability:

This form of reliability is akin to splitting a novel into two halves and expecting the storyline to remain consistent. If a test on shyness, for instance, yields conflicting insights when comparing odd-numbered questions to even-numbered ones, its overall consistency is jeopardized.

Alternate Form Reliability:

It’s like watching two trailers for the same movie. Both should give you a similar idea about the movie’s storyline. When psychologists create two distinct forms of the same test, an individual’s scores on both versions should be in harmony, ensuring that the test’s content and criteria are stable.

Resources for Enthusiasts

The world of psychology offers myriad resources for those yearning to delve deeper. The study, “I Scream, You Scream: Teaching Validity and Reliability Via the Ice Cream Personality Test,” brilliantly fuses the world of gastronomy with the principles of psychology. For a more nuanced understanding, the Distorted Tunes test and the What is Reliability page on further illuminate the multifaceted nature of test reliability.

In Conclusion

In our pursuit of understanding human nature and individual personalities, the tools we use must be built on the bedrock of reliability. This ensures not only their scientific validity but also their capability to truly reflect an individual’s unique persona. As the adage goes, the quality of answers one receives is directly proportional to the quality of tools one employs. Reliability, in this context, isn’t a mere technicality; it’s the very essence of trustworthiness. Choose your tools with discernment.

Resources on Personality and Reliability

    • Miserandino, M. (2006). “I Scream, You Scream: Teaching Validity and Reliability Via the Ice Cream Personality Test.” Teaching Psychology. 33(4), 265-68.
    • The Distorted Tunes test
    • The What is Reliability page on lists a few more types of test reliability.


About Author


  1. Avatar

    app store rankings

    January 19, 2012

    I particularly enjoy your views on Reliability –
    the Foundation of Any Good Personality Test and also I will bookmark this..

    Bye for now!!

  2. Avatar


    January 19, 2012

    Yes, you’re right Stu: a lot of things change during the adolescent years, so it’s possible for a test score to change during a year and thus it could be seen as unreliable – at least as compared to the score a year earlier. Good point. I was thinking of aspects of adults that typically don’t change from year to year.

    Glad you’re enjoying the podcast!

  3. Avatar


    January 19, 2012

    have a question to do with reliability. you mentioned how if you came back in a year your results could be the same. true this should be in most people like adults. i was wondering if this is the same with teenagers and adolescents as i believe personalities could change due to life changing events or concepts in the idea of life. maybe this links to eysenck’s dimension of neuroticism. or maybe im over complicating the issue. any way it was a good episode, keep ’em coming

  4. Avatar


    January 19, 2012

    AJ: Glad you liked this episode. I decided to discuss reliability and validity in separate episodes. Heard that joke about the “two types of people”. It’s a goodie.

  5. Avatar

    AJ Jack

    January 19, 2012

    Great to see you getting into the subject of personality tests, a favourite topic of mine.
    I am looking forward to the follow-up episodes.
    I personally think there are only two types of people in the world, those who split people into two group and those who don’t.

Leave a comment

Your email address will not be published. Required fields are marked *

You may also like

Critical Thinking Research and Stats

Episode 3: Predictions, Predictions

Have you ever heard of someone who says they can predict the future? Perhaps you’ve seen magazine articles in which
Personality Therapy

Episode #5: In Defense of Defense Mechanisms

Too many people dismiss Freud because he had a few controversial ideas, but as I try to point out in