## 3 Results and Discussion
### [PERSON]'s Heuristics
#### 3.1.5 Prevent Errors  
Scratch prevents errors. For example, it is not possible to type a string from a form field intended for a number. However, its rating was downgraded due to a lack of user feedback parts, e.g., flaws in providing hints and suggestions. This can lead to frustration, as users may not be aware that the action they take is wrong, which, in turn, can lead to the erroneous belief that the program does not function correctly. App Inventor also prevents errors, e.g., by checks of data types, preventing combination of some incompatible elements, and highlighting problematic elements. Although, due to its complicated nature, the user might be better informed which design leads to erroneous applications, which is sometimes clear after its installation on a mobile device. Simple error cases are correctly addressed. StarLogo prevents errors in a similar way to Scratch. It quite frequently provides error warnings, although not in all cases, which might lead to confusion for users. 3.1.6. Show Instead of Forcing to Remember  
Scratch satisfies this heuristic. Navigating the editor is intuitive. Every action is easy to replay. Code blocks are color-coded to indicate their purpose, so the user can easily find the item they need without having to search through all the sections. App Inventor satisfies this heuristic just like Scratch. What is more, when providing the Designer and Blocks editor views, all useful information from a different view is repeated. StarLogo does not fully meet this heuristic, so it is rated lower. The names of some blocks require the user to be familiar with the environment. What is more, navigating the editor can cause some difficulties, as it has been divided into three main screens and the user is not fully supported with the relevant information from the other screens. 3.1.7. Ensure Flexibility and Efficiency  
Scratch works efficiently, and the user is not forced to wait for individual elements of the interface to load. However, the issue of flexibility poses a problem. Despite a large number of selectable interface languages, several other basic accessibility features are missing: there is no option to enlarge the interface font (workspace window has to be zoomed), a dark mode and a high contrast mode are also missing (the former is expected to be available in the near future). App Inventor works efficiently in most cases. Although, when dealing with large applications, the area of a model is so large that it needs to be scrolled. When working with big models, the user might wish for smaller elements in order to see as much of the model on a single screen as possible. Some flexibility issues known from Scratch are present as well. App Inventor offers many language versions that address universal languages and languages of smaller but active societies. StarLogo works efficiently, and the user is not forced to wait for individual elements of the program to load. However, flexibility poses similar problems as in the case of Scratch. Moreover, only an English version is available. 3.1.8. Take Care of Aesthetics and Moderation  
The Scratch interface is aesthetically pleasing and minimalistic and keeps all the useful information on the page. Both the color palette and the arrangement of individual elements are planned at a high level. The heuristic is fully met. App Inventor is aesthetically pleasing and keeps all the useful information on the page. Nevertheless, working with big models and a large number of element types on pallets might be unfavorable, although, due to App Inventor's domain specificity, it seems to be unavoidable. StarLogo received a noticeably worse rating, as its interface is not minimalistic and aesthetically pleasing. Mismatching high saturation colors were selected. In addition, the page layout is vertical, which also affects its unfavorable appearance. 3.1.9. Ensure Effective Error Handling  
This heuristic has been downgraded in the case of all environments due to improper error handling.