Lesson Plan – Discrete vs. Continuous Data
Summary
This activity will help students distinguish between discrete and continuous data. Students will read graphs and hypothesize about missing data using discussion and small-group brainstorming. This activity will help students understand how important glider technology is to ocean observing system scientists.
Key Concepts
· Technology used to gather data enhances accuracy and allows scientists to analyze and quantify results of investigations.
· Communicate and defend a scientific argument.
· Recognized and analyze alternative explanations and predictions.
Objectives
Students will be able to:
· Describe discrete versus continuous data and how they are measured.
· List advantages and disadvantages of measuring data using autonomous gliders.
Materials
· Both sets of two Rutgers University glider plots either printed onto transparencies or integrated into Microsoft PowerPoint.
· Depending on available technology:
o Computer with Microsoft PowerPoint, or
o Overhead projector
Procedure
1. Go to the Rutgers University COOL Projects website: <http://www.coolclassroom.org/cool_projects/lessons/miniunits/lesson1.html>.
· Ask students to hypothesize about how the scientist in the video ends up on the ground.
2. When ready, play the video on the website to reveal how the scientist actually ends up on the ground.
3. Discuss the assumptions the students had and introduce the ideas of discrete vs. continuous data.
4. Show students, either via PowerPoint or transparency Figure 1 (below).
· Explain that this figure represents data acquired by scientists on a research vessel using a CTD (see Web Resources) to obtain data (discrete data).
5. Ask students to hypothesize about the missing portions of the graph, what happens in between the various discrete data sets.
· Have students fill in the graph as to what they believe the trend is.
6. When ready, display Figure 2, which reveals the missing portion of the graph.
· Explain that this figure represents data acquired by scientists utilizing glider technology (continuous data).
7. Discuss why or why not the students’ hypotheses were correct.
8. Repeat steps 4-7 with Figures 3 and 4, which do not follow an assumed trend, and instead displays substantial differences in the densities of different water masses.
· Cold, fresh water top left of figure; Cool semi-saline water moving overtop warmer salt water in middle of figure; Warm salt water mixed through out in far right of figure; A front directly in the middle of the figure.
9. Discuss the importance of measuring this data continuously.
10. In small groups, have students produce a list of advantages and disadvantages of measuring data via autonomous (independent) gliders vs. in situ CTD casts.
AssessmentPerformance: Did student participate in the discussions before and after the video and graphs were revealed and understand the concept of discrete vs. continuous data? Did student participate in the discussion of the importance of measuring data continuously versus discretely?
Product: Did group produce a list of relevant, accurate advantages and disadvantages of using autonomous gliders?
Web Resources
· Introduction to the CTD (Conductivity, Temperature, and Depth):
Ø http://www.windows.ucar.edu/tour/link=/earth/Water/CTD.html&edu=high
Ø http://coexploration.org/bbsr/classroombats/tour/html/ctd.html
· Introduction to AUVs (Autonomous Underwater Vehicles):
Ø http://marine.rutgers.edu/cool/technology/gliders.htm
Ø http://en.wikipedia.org/wiki/Autonomous_Underwater_Vehicle
Extensions
1. In small groups or individually, have students create a salinity profile that would coordinate with Figure 4, based on what was discussed in #8.
Objectives
Students will be able to:
· Apply knowledge of effects of salinity on density.
· Generate a graph based on data that was discussed in class.
2. Have students do webquest or research projects, with or without PowerPoint presentations, on different types of ocean observing equipment, e.g. submersibles, gliders, CODAR, REMUS
3. Glider profile “dissection.”
Examples: Scale, Bathymetry, Charting (Lat/Long), Effects of currents
Figures
Figure 1. Original source: http://marine.rutgers.edu/~kerfoot/glider_portal/archive/gliders/060531-060602-ru05/data_products/cross_sections/ru05_060601T2108_060602T1445_eline_temp_xsec.jpg
Figure 2.
Figure 3. Original source: http://marine.rutgers.edu/~kerfoot/glider_portal/archive/gliders/060518-060524-ru07/data_products/cross_sections/ru07_060518T1748_060524T0939_eline_temp_xsec.jpg
Figure 4.
Figure 5. For Activity Extension #1. Source: http://marine.rutgers.edu