Case Study – Comparison of classic and ReDem® cleaning using the Magenta Smart-City study

In this article, we shed light on the effects of ReDem® data cleaning on the interpretation of the results of the Magenta Smart City study.

The study was conducted by TripleM – Matzka Markt- und Meinungsforschung on behalf of Magenta Business and cleaned by ReDem®.

This study impressively shows how the data cleaning by ReDem® has an effect on the data interpretation in comparison to conventional cleaning. Particularly in the case of complex questions, the use of ReDem® for data cleaning is of great importance in order to derive well-founded recommendations for action.

Survey design | Description of the survey

For the cleaning of the raw data of the Magenta Smart City study, first the conventional cleaning of speeders, straightliners and also the control of open ended answers, was performed manually in a multi-step procedure by TripleM.

In comparison, the raw data were also checked according to these quality criteria in a standardized way with ReDem®. In addition, projective control questions were integrated to identify superficial response behavior with the so-called "ReDem prediction score". Subsequently, the data were scored as well as cleaned using our ReDem® Score. The ReDem® Score combines all relevant quality criteria and thus enables a transparent and objective assessment of the data quality.


The following excerpts from the Smart City study show the effect of the ReDem® cleaning compared to conventional cleaning.

Influence of the cleaning on social demographics

Social demographics are barely changed by the ReDem® adjustment.

Awareness of the term "Smart City"

In the case of the term "Smart City", the ReDem® cleaning brings a slight increase. Here, too, no major change was expected as a result of the ReDem® cleaning, as this is a relatively simple and clear question.

Importance of community/city becoming smart city?

The importance of Smart City to one's community would be significantly underestimated WITHOUT the ReDem® cleaning.

Without the cleaning by ReDem®, there would be a differentiated interpretation of the data. The importance increases by over 10 percentage points, to 75,9 percent.
This question was an important element of the entire study and essential for a valid result.

Due to the more complex content of the question, the effect is very clearly seen through the ReDem® cleaning.

Assessment of Smart City—agreement with statements

The cleaning by ReDem® shows partly significant differences in the assessment of Smart City.

This example illustrates once again that the probability of superficial response behavior is very high for questions that require a higher cognitive effort from the respondents.

Increasing the quality of the sample

The ReDem® cleaning increases the ReDem® Score of the whole sample by 14 points to 81 points
The ReDem® Score measures data quality, with a score between 0 and 100, before and after cleaning.


The Magenta Smart-City study showed that superficial responses are common, especially for complex questions with higher cognitive effort. This underlines the importance of ReDem® cleaning to minimize bias. The study clarifies which questions are more vulnerable to superficial responses and which are less so.

Click here for the press release of the study:

Florian Kögl
Florian is the founder and CEO of ReDem®. He is also a board member of the Austrian Market Research Association and has extensive experience in the development of innovative software solutions.