Affix knowledge test and word part technique


There is a new online test, the CAT-WPLT (computerized adaptive testing of Word Part Levels Test) to assess students word part knowledge, i.e. prefix, suffix and stems (though the test only uses affixes for receptive use). The (diagnostic) test is composed of three parts – form, meaning and use. The form part presents 1 real affix and 4 distractor affixes for the test user to choose. The meaning part presents 1 correct meaning and 3 distractor meanings and the use part presents 4 parts of speech to match one of these correctly to the affix.

Try out the test – CAT-WPLT.

The online test takes about 10-15mins to complete and results in a nice feedback screen showing how the test taker did on the form, meaning and use of the affixes. There are comparison advanced, intermediate and beginner profiles.

Figure from Mizumoto, Sasao, & Webb (2017) pg. 14

So say you have a profile of a student who shows weakness in form and meaning. What now? Mizumoto,  Sasao, & Webb (2017) suggest giving learners their pdf list of 118 affixes (assuming you don’t need to use the test again). So if your learner is at level 1 for recognizing the form of an affix, the affixes listed as level 2 can be focused on.

Another possibility is a memory technique called the word part technique.

Word part technique
Very simply it is using an already known word which contains the same word stem/root as the new word to be remembered.

More specifically the system Wei and Nation (2013) describe lists very frequent stems i.e. stems which appear in words in the most frequent 2000 words of the BNC. These are then used to learn stems appearing in the remaining 8000 mid-frequency words in the BNC wordlist. For example a high frequency word like visit has the root -vis- which appears in mid-frequency words such as visible, envisage, revise.

Once a form connection is seen between a known high frequency word and a mid-frequency word a meaning connection needs to be made i.e. explaining the form connection. So to explain the word visible we can say visible is something that you can see. Here the explanation uses the meaning of -vis- i.e. see.

(high freq. word) visit -> go to see someone
(stem)                  vis -> see
(mid-freq. word)  visible -> something that you can see

According to Wei & Nation (2013) the most difficult step is explaining the connection. Though I think the most difficult is the first step – seeing the connection i.e. the stem/root word. Wei & Nation (2013) encouragingly state that making the connection and explaining it can develop with practice.


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Click here to see top 25 word stems taken from Wei & Nation (2013)

They go on to recommend that once students have worked with this technique with the teacher they can go on to use it themselves as a strategy.

The technique’s efficacy is on par with the keyword technique and learners own methods or self-strategies (Wei, 2015). The word part technique has the added benefits that come with the nature of etymology and the history of words.

Thanks for reading.


Mizumoto, A., Sasao, Y., & Webb, S. A. (2017). Developing and evaluating a computerized adaptive testing version of the Word Part Levels Test. Language Testing, 0265532217725776.

Wei, Z., & Nation, P. (2013). The word part technique: A very useful vocabulary teaching technique. Modern English Teacher, 22, 12–16.

Wei, Z. (2015). Does teaching mnemonics for vocabulary learning make a difference? Putting the keyword method and the word part technique to the test. Language Teaching Research, 19(1), 43-69.