Dear Anika, thank you for your question!
We looked into different usability questionnaires which were already available. We had 3 different steps in filtering our items.
The first step was to finds items that had a factor loading of 0.7 on usability. These 18 items were taken from four different questionnaires (PSSUQ, SUS, WAMMI, AltUsability).
After taking a further look, we realised that some of those items are quite diffucult to visualise, so we alternated some of our items and took some of them out. This lead us to 16 items.
And after doing a comprehension check of the pictorial items, we deleted 4 and ended up with 12 items.
So basically those 3 steps were looking for items, visualising the items and filtering the comprhensible items.
If you have any further questions, don't hesitate to ask!
We looked into different usability questionnaires which were already available. We had 3 different steps in filtering our items.
The first step was to finds items that had a factor loading of 0.7 on usability. These 18 items were taken from four different questionnaires (PSSUQ, SUS, WAMMI, AltUsability).
After taking a further look, we realised that some of those items are quite diffucult to visualise, so we alternated some of our items and took some of them out. This lead us to 16 items.
And after doing a comprehension check of the pictorial items, we deleted 4 and ended up with 12 items.
So basically those 3 steps were looking for items, visualising the items and filtering the comprhensible items.
If you have any further questions, don't hesitate to ask!