# Research design

The research question are examined in more detail by means of a qualitative hypothesis generating case study. Therefore the GeoGebra applets are used in a 7th grade of a middle school in Austria. The qualitative analysis is carried out using methods of Grounded Theory (Glaser & Strauss, 1998). The data collection is divided into a process that involves five stages.

## Data collection

• Stage 1: Diagnostic test 1
• Contains tasks concerning different pre- and misconceptions;
• Then students are divided into 2 groups;
• Stage 2: Diagnostic interviews
• Concerning tasks from diagnostic test 1;
• With 8 students of group 2;
• Stage 3: Intervention
• Use of GeoGebra applets in class;
• Students working independently in pairs;
• Duration: 3 lessons;
• Recording (audio, video, screen) of students of group 1;
• Stage 4: Diagnostic test 2
• Contains tasks concerning conceptions slightly different from diagnostic test 1;
• With all students;
• Stage 5: Diagnostic interviews
• Based on analysis of recordings and diagnostic test 2;
• With 8 students of group 1;
If necessary interviews with teachers about the design of the applets will be conducted.

## Diagnostic test 1

Here are some tasks of the diagnostic test 1. The first two tasks (Area, Skier) are according to examples from Schlöglhofer (2000). The third one is from a german test instrument called CODI, which has been designed by Nitsch (2015) to diagnose misconceptions concerning functional relationships.

You see a skier who is descending a slope. The graph shows the speed of the skier in the course of time. Which of these 4 diagrams is describing the situation best?

Here a trapezoid is displayed. Imagine you draw the dotted line from vertex A to the right by the distance x. In doing so you observe the changes in the size of the grey marked area.
In the diagram the grey-shaded area is a function of distance x. Which of these 4 diagrams is correct?