But reader testing can be expensive. You need equipment and training to conduct eye-tracking studies. Thanks to two of my Dutch colleagues, Menno de Jong and Peter Jan Schellens, there is a simple and inexpensive technique I recommend. In fact, we have our undergraduate business students use it.
In the plus-minus technique, the writer recruits a few representative readers. More and better representatives give you better results. (Here’s a free report from experts on recruiting folks for this kind of testing.) The writer gives the readers the draft document and collects their impressions.
Here are the instructions we provide readers for document testing.
Please read the entire document, including the parts that you would probably skip “in real life.” Take your time. Read the document at your own speed.
1. While reading, we want you to place a plus (+) and a minus (-) in the margin anytime you judge something as positive or negative. But do not think too long about your impressions. Any plus or minus is okay, as long as it reflects what you are thinking as you read.
For example, if you find something in the document funny, interesting, clear, or important, write a plus. If you find something in the document not interesting, unclear, or unimportant, write a minus. You can write down pluses and minuses for any reason.
2. Please indicate which part of the document a plus or minus applies to by circling or underlining it.
Decide for yourself which units of the document to mark with a plus or minus. For instance, you can write down a plus or minus for a paragraph, a heading, a sentence, a word, an illustration, or a caption.
3. When you have finished, we will ask you to talk about your impressions of this document.
After the readers are finished, someone debriefs them. This can be the writer — although it’s probably best if the reader doesn’t know the interviewer wrote the draft. Here are the instructions we provide for the interview.
Tell the reader you would like to learn about their impressions of the document so that it can be improved. Remind him/her that all of his/her responses are important to you. Ask if you can audiotape your interview. If you do not audiotape, make sure you go slowly enough to get all information written down.
Ask the reader to describe what they were thinking for each plus and minus. Get the reader to be as specific as possible about the places where he or she felt positively or negatively. You must be able to identify specific words, paragraphs, headings, figures, etc. later during your analysis of the results. As soon as possible after the interview, summarize your interpretation of the reader’s responses using the questions below. (Not all questions will be relevant for all interviews.)
- Does the reader correctly understand the given information? What worked well? What is unclear?
- Will the reader pick up the document and start reading it? Why or why not? Will the reader focus on the most important information? Why or why not?
- Can the reader apply the given information in a productive way and in a realistic setting? What seems to be most helpful? Where does the reader go wrong?
- Does the reader find statements to be credible? Which ones? Why or why not?
- Does the reader like the way or the order in which information is presented? What worked well? What needs to be revised?
- Does the reader get new, relevant and complete information? What does the reader like? What does the reader want to skip?
The results you collect from representative readers will identify any major issues with your draft and help you determine what should be revised before you deliver the document to your actual readers.
The plus-minus technique allows you to balance the importance of concurrent testing (i.e., learning what the reader is thinking in real time) with the simplicity of retrospective testing (i.e., learning what the reader thinks after he or she has read your document). You can learn more about reader testing (usability testing) from the Center for Plain Language or the Nielsen Norman Group (user testing).