With Sticky, you can understand the participants' engagement by checking if your text was read or not.
When you select your areas of interest (AOI), you can input the number of words contained in that piece so we can calculate how likely it is that participants read the content.
After completing the experiment, you will find two metrics in the AOI statistics file: Read Guidance and Read Percentage.
Read Guidance is the success rate of your text within the AOI based on the Read Percentage (RP) and is defined as following:
Read - RP ≥ 70%
Glanced - 50% ≤ RP < 70%
Skimmed - 0 ≤ RP < 50%
We consider it a fail if less than 70% of your AOI was read by participants which means you might not be conveying the message.
Read Percentage is the average percentage of a text read in the AOI. To define the read percentage, we need to understand the two parameters involved: "words" and "reading speed".
For the English language, word is defined as a sequence of 5 characters on average when considering a large enough text. This an assumption that will hold for several romance languages and others using Latin/Cyrillic alphabets. The exception is for languages with compound words (e.g. German, Swedish) which can be broken down into smaller words and might be considered as two or more when selecting word count.
Notice the average word length is not defined by the average of all words in a certain language, but on how they are actually used together, which is what we are interested in.
Setting up the number of words instead of the number of characters is favorable for a few reasons, such as the eyes having an acuity of seeing groups of characters as one entity instead of individual ones and these groups roughly match the average word size.
For eastern languages, such as Mandarin Chinese, the words are much shorter with 1.5 characters on average, but the reading speed of words is still comparable to English given the complexity of the characters involved. Therefore a universal solution is more accurate with the metric being words and not characters.
Having decided on words as the base metric, we need to see how many words a participant would be able to read in the amount of time they looked at the AOI. Average readers in the English language are capable of 200-250 words per minute (WPM), while good readers can go well past 300 WPM.
There is a trade-off between how well someone can understand the information read and how fast they can read which should be taken into consideration in the marketing world with ads where people might want to read it fast and move on to other things.
In that sense, our calculations will consider an average 300 WPM equivalent to 5 words per second when delivering the Read Percentage metric.
Reading percentage calculation
The final calculation after defining words and reading speed is
RP = (Time viewed × words per second / word_count) × 100