Project

What does Sensafety do?

Sensafety captures the general subjective feeling of safety at a site and makes the results available to citizens in an aggregated form in the App.

What is the research objective of the Sensafety project?

The research objective of the project is to record the subjective perception of safety at a location and to compare it in the long term with statistical crime and accident data and other safety-relevant indicators.

What is perceived safety?

The perceived safety is the subjective safety perception of a person depending on the situation.

Are you a company?

No. We are a research group of the Technische Universität Berlin in Germany.

Ratings

How often can I rate?

Each user is allowed to rate the safety situation at her/his location only twice a day: once during the day and once at night. The day/night change takes place at sunset or sunrise.

Can I undo or delete my rating?

No

Does the app take into account whether I am inside a building or outside?

No

Why am I not allowed to rate?

You have already rated the safety situation at your location. Either change your location or wait until it gets night or day so you can rate again. Each user is allowed to rate the safety situation twice a day at a location: once during the day and once at night. The day/night change takes place at sunset or sunrise.

How far do I have to move to be allowed to rate again?

Move at least 150m in any direction in order to be able to rate again.

Map

What do the colored rectangles on the map mean?

In a rectangular area (zone), the ratings of all users are aggregated. The average of all ratings is then represented by the respective color of the zone. Green stands for high perceived safety, yellow for moderate perceived safety and red for low perceived safety.

What do the colours on the map mean?

Green stands for high perceived safety, yellow for moderate perceived safety and red for low perceived safety.

What does the number at the top left of the map mean?

The number indicates the sum of all ratings from the visible area of the map.

What do the symbols Sun, Moon and Sun/Moon at the top right of the map mean?

If the sun is activated, the perceived safety during the day is displayed. If the moon is activated, the perceived safety at night is displayed. If both symbols are activated, the perceived safety is displayed regardless of the lighting conditions.

How is the average feeling of safety calculated?

The average feeling of safety of a zone is determined using the statistical method of exponential smoothing. More recent evaluations have a higher influence on the calculated average value than older evaluations.

Compass

What do the colors and sizes on the outer edge of the virtual compass mean?

The colors reflect the average value of all ratings given in a given direction. Green stands for high perceived safety, yellow for moderate perceived safety and red for low perceived safety.

What does the size of a colored area at the outer edge of the virtual compass mean?

The size of a colored area at the edge of the compass indicates how many ratings are taken into account when calculating the average perceived safety. The larger the area at the edge of the compass, the more ratings will be considered.

Privacy

What personal data is transferred to the Sensafety project?

Each of your ratings will be submitted to the Sensafety research project. A submission contains the time of the rating, the place of the rating, the result of the rating and a device-specific identification number (device ID).

Why does the Sensafety project need the device-specific identification number (device ID)?

This will technically ensure that each user is only allowed to submit a rating for his or her location twice a day at the most.

Can I make my ratings anonymous?

Your ratings are already sent to the Sensafety project in pseudoanonymized form. The Sensafety project stores the unique identification number of your mobile device, but it cannot infer the person behind the rating. If you still want your ratings to be completely anonymous, use the button "Anonymization request" in the App under Settings/App-Info.

What happens to my ratings if I make them anonymous?

Each of your ratings is marked with your device-specific identification number. An anonymization of your ratings leads to the deletion of the device-specific identification number. This means that the ratings are no longer associated with your device and are therefore no longer visible in your history.

Can I undo the anonymization?

No. Since the ratings are anonymous, it is no longer possible to determine the originator of the ratings.

Will I lose my history if I make my reviews anonymous?

Yes

What happens after I have given a rating?

If you have submitted a rating, it will be transferred to us. We combine the ratings of all users in your zone and calculate an average value. The result can then be seen in the form of the colored zones on the map, in the augmented reality view or the virtual compass.

How long are my ratings stored?

According to the "Statute on the Safeguarding of Good Academic Practice" at the Technische Universität Berlin, your ratings will not be stored for more than 10 years for research purposes.

Will my personal data be passed on to third parties?

No. All collected personal data remain the exclusive property of our research group at the Technical University of Berlin. However, our research group reserves the right to share ratings in anonymous form with research partners for non-commercial research purposes.

Can other users see my ratings?

Other users can only see the average of the ratings of all users in a zone. Your individual ratings are hidden from other users.

Miscellaneous

Does the history remain available after a new installation of the app?

No

Can I transfer my history to another smartphone or tablet?

No. Ratings are always tied to the device.