My IoT Puzzle: Debugging IF-THEN Rules Through the Jigsaw Metaphor

Abstract

End users can nowadays define applications in the format of IF-THEN rules to personalize their IoT devices and online services. Along with the possibility to compose such applications, however, comes the need to debug them, e.g., to avoid unpredictable and dangerous behaviors. In this context, different questions are still unexplored: which visual languages are more appropriate for debugging IF-THEN rules? Which information do end users need to understand, identify, and correct errors? To answer these questions, we first conducted a literature analysis by reviewing previous works on end-user debugging, with the aim of extracting design guidelines. Then, we developed My IoT Puzzle, a tool to compose and debug IF-THEN rules based on the Jigsaw metaphor. My IoT Puzzle interactively assists users in the debugging process with different real-time feedback, and it allows the resolution of conflicts by providing textual and graphical explanations. An exploratory study with 6 participants preliminary confirms the effectiveness of our approach, showing that the usage of the Jigsaw metaphor, along with real-time feedback and explanations, helps users understand and fix conflicts among IF-THEN rules.

Appendix: Rules Used in the Evaluation

The following trigger-action rules were used in the evaluation of My IoT Puzzle:

• R1. If your Android smartphone detects that you enter the home area, then turn on the Philips Hue kitchen lamp.

• R2. If your Android smartphone detects that you enter the home area, then turn off the Philips Hue kitchen lamp.

• R3. If your Android smartphone detects that you enter the home area, then turn on a color loop on the Philips Hue kitchen lamp.

• R4. If a new photo is added to the “ios” album on iOS Photo, then add the file on the “drpb” Dropbox folder.

• R5. If a new photo is added to the “drpb” Dropbox folder, then upload the photo on Facebook.

• R6. If there is a new photo post by you on Facebook, then add the photo to the “ios” album on iOS Photo.

• R7. If your iPhone detects that you exit the work area, then lock the SmartThings office door.

• R8. If the SmartThings office door is locked, then arm the Homeboy office security camera.

• R9. If the Homeboy office security camera is armed, then unlock the SmarThings office door.

• R10. If a new song is played on Amazon Alexa, then post a tweet with the song name on Twitter.

• R11. If a new song is played on Amazon Alexa, then save the track on Spotify.

• R12. If a new track is saved track on Spotify, then post a tweet with the song name on Twitter.

The rules generate 2 inconsistencies, 2 redundancies, and 1 loop:

• R1 and R2 generate an inconsistency, because they share the same trigger while producing contradictory actions on the same device;

• R7 and R9 generate an inconsistency, because they produce contradictory actions on the same device and are activated nearly at the same time, since R7 activates R8, and R8 activates R9;

• R1 and R3 generate a redundancy, because they share the same trigger while producing two similar actions on the same device;

• R10 and R12 generate a redundancy, because they produce similar actions on the same online service and are activated nearly at the same time, since R10 and R11 share the same trigger and R11 activates R12.

• R4, R5, and R6 generate an infinite loop, because R4 activates R5, R5 activates R6, and R6 activates R4;