1. Group Roles Leader - Directions  Reads the experimental design.  No one does anything without being told to.  Reminds peers about their roles.  Settles disagreements.  Records data on laptop while reading data slip. Technician - Measurements  Pulls the block w/ spring scale.  Remembers which line the force was measured at.  Determines the magnitude of the force. Remembers which line the force was measured at. Determines the magnitude of the force. Data Manager Records force magnitudes on appropriate data slips while saying the sentence out loud to the group. Collects data slips. Quality Control – Checks Measurements

2. Friction Lab Procedure  Groups are called to the marbles station.  Groups rotate freely between stations. On periphery and their own tables.  Backpacks under tables.  Keep your own block the whole time.  Stay with your group.  Voice level 2.  1 Period for Data

3. Video… Spot the mistakes