OM book glossary

This is the glossary for the book “Outcome measures and evaluation in counselling and psychotherapy” written by myself and Jo-anne Carlyle and available now from SAGE. I am over 430 entries now and still climbing though now (April 2026) I am concentrating more on harmonising, cleaning up and cross-linking existing entries than I am on adding new ones. Some glossary entries link to more detailed expansions of the topic in my Rblog and, at last, an increasing number now link with interactive online (“shiny”) apps.

You can see the alphabetical list of entries below which is a good place to browse, or you can use this search box.

Beware: the way the search orders the matches is to my mind bizarre so scroll down if what you typed isn’t first on the list, you may find something with exactly the title that is exactly the phrase you typed in to find is hidden down the list of suggestions.

If what you want is not there and you think it should be, contact me and tell me and I will put it on the (long!) list of entries to be added!

C

Cross-loading (factor analysis)

You're only likely to see this in reports of exploratory factor analyses of measures. Details The term…

Chi squared test

You may see this written as "chi-squared", "chi square", "chi-square" or "chisquared" or as using…

Cronbach's coefficient alpha

Despite much criticism, almost all of it criticising people for using Cronbach's alpha without really…

Content validity

This is mainly about typical multi-item nomothetic self-rating questionnaires or rating scales. Content validity…

Cutting points

In our field this refers to scores that are deemed to separate "help seeking" and…

Cluster analysis

Pretty much what it says: a family of statistical methods that look to see if…

Cross-lagged correlation

What it says really! A statistical method that explores the relationship between two variables…

Change vs. outcome

This is just my own pedantry and here to encourage others to think about it…

Covert vs. overt items

The name is pretty accurate: it's about whether items in self-report questionnaires are overt about…

Clinician-reported outcome measures (ClinROMs, CROMs)

These are a subset of Clinical Outcome Assessments (COAs) and were essentially the only change/outcome…

More

Creation date lost, updated 19.v.24 to add the new BetterDocs “encyclopedia” listing of entries, tweaks 13.iv.26. Author CE; this page and all glossary contents are copyright to me so contact me if you want to quote from them (I’m sure I’ll agree!). That may change to a Creative Commons licence later when I am happier with the content.