Education Technology

Collecting Data

Published on 06/09/2008

Activity Overview

In this activity, students investigate how to use random numbers to collect samples and how to randomly assign subjects to experiments to collect data. They also use the CBL system to collect data in real time.

Before the Activity

  • Connect the calculator to the CBL 2™
  • Connect the temperature probe to the CH2 port of the CBL 2 unit
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 45 - 50 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to the class.

    Follow the Activity procedures:

  • Use the calculator to generate random numbers to select a committee of eight students from a class of 24 students with 15 females and 9 males
  • Use stratified sampling and random number generation to select another committee of eight that maintains the proportion of females (5) and males (3) that are in the class
  • Divide the class into two random groups using the first 12 numbers randomly generated to form the first group and the remaining forming the second group

  • Newton's Law of Cooling:
  • Keep the temperature probe at room temperature and record the temperature for 30 seconds
  • Place the temperature probe in hot water and record temperature for a few minutes
  • Record the room temperature
  • Remove the probe from the water and measure temperature
  • Note that the temperature continues to drop, leveling off to the room temperature
  • Observe the temperature versus time graph
  • Identify that the rate of change of temperature is proportional to the difference between the temperature of the liquid and room temperature
  • Perform an exponential regression and determine the best fit equation
  • Graph this equation
  • After the Activity

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary