This is the test I use for each of my WTW groups. The test has 3 parts:
1. Students are given 10 words from their current sort.
2. Students are given 10 words NOT from their current sort that follow the same spelling pattern. This is to see if they are able to apply the learned rule(s) to new words.
3. Students are given 5 high frequency words to study for each cycle. I assign different words for each of my 4 groups, but you could differentiate it even further and have each child choose their own words to study OR if that seems like too much to manage, have the same 5 words for the whole class to study.