Discrete versus Continuous

This lesson was adapted for classroom use by COSEE NOW member Laura Dunbar.

Synopsis of the Activity

Discrete versus Continuous

This experience enables students to see how using continuous data provides a better understanding of what is actually happening.

Students will view a series of pictures (discrete data) and determine what is happening. With the data given, it appears that a woman fell off the pier onto the marsh. Afterwards, the students watch a video (continuous data).

Now that they have more information, their idea of what really happened changes. They see she regained her balance after teetering on the pier edge and then walks down the stairs, tripping at the bottom to end up flat-out on the marsh.

It’s important to let the students experience the difference between the two forms of data and not “give away” the ending.

This experience can be done quickly as a whole class discussion (5 minutes), or expanded to explain the difference between observations and inferences (20 minutes).

Audience

Grade 4 to college

Objectives

The primary objectives are to:

1. engage the students as scientists by having them practice making good observations
2. demonstrate the difference between discrete and continuous data
3. demonstrate the importance of collecting different types of data
4. expose the students to real time data (optional)

Materials

• A method for students to see the PowerPoint, either large screen or individual computers for each student (computer lab)
• What is discrete data?
• Continuous movie
• Student worksheet (optional)

Procedure

1. Discussion: Making observations is an important skill for scientists. An observation is a fact gathered by using the 5 senses.
   Ask: What makes a good observation? (details, exact measurements when possible)
2. Practice making good observations. Show the students the first picture in the PowerPoint. Students can either write down their observations on the student worksheet, or volunteer them in a class discussion. (Because this activity sets them up to come to a “wrong” conclusion and some students may feel that you made them look stupid in front of their peers, it may be better to have them write down their observations.)



3. Continue to the next photo in the PowerPoint. Students continue to make observations. Continue for all the photos. The last photo is the 2nd one in which she is flat-out on the marsh, looking up, smiling (so they know she is OK).
4. Ask the students to develop on inference about what happened. (If using the handout, they just write it down. If using the class discussion format, have students share their ideas with the person next to them or in groups).
   Note: An inference is a conclusion based on observations. While observations are facts (and therefore never “wrong”), inferences are an interpretation of those facts (and may not be completely correct).
5. Explain that photos are similar to discrete data (separate bits of information). They provide information in a limited timeframe: literally a snapshot in time. Video is similar to continuous data in which much more data is available.
6. View the video. Ask students if they would like to revise their inference based on the continuous data.
   Note: It’s important to emphasize that the discrete data was not incorrect or wrong, just not enough information. The continuous data provided a better understanding of what actually happened.



7. Provide the students with some or all of the following information:
   • Ocean research is an example of where continuous data has changed our view of the world
   • An example of ocean data gathered as discrete data is a ship sailing to a particular spot and to measure temperature, salinity, currents, wind speed and direction, etc.
   • Example of ocean data gathered as continuous data is satellite data, glider data and buoy data.

Extension

Display data (computer or printout) from instruments that collect data on the ocean. To view real-time data generated from gliders deployed all over the world, access the Rutgers University Glider homepage at http://marine.rutgers.edu/cool/auvs. If no glider missions are currently underway, please access the glider archives.

Note: Be sure to orient the students to what they are looking at. Show where depth is, and where distance along the line the glider traveled is. Point out that colors represent different number values the glider measured. It’s easiest to do this for temperature – red for warmer water, blue for colder.