Applied Science - Science and Math (5A) Lab
 OBJECTIVES: Estimating data and comparing results on graphs. Interpreting the margin of error. VOCABULARY: bar graph estimation guess margin of error prediction MATERIALS: 2 sizes of marbles, beans, beads (you can substitute any of these items) containers or beakers (optional). Students predict number of items in a container.
 BACKGROUND: When scientists tell others about their work, they frequently display their data using charts and graphs.  Graphs and charts can be easily read and interpreted.  This makes them an effective means of communication.  Graphs and charts have been used since written record was developed, and graphing techniques are still used today.  There are even computer graphing programs that help scientists, economists, statisticians, and many other people interpret data easily. In this lab, students make a bar graph to record estimated quantities of items and then compare the actual amounts.  Place different items in different containers or beakers.  If using the module, store the materials in the plastic bags.  Items can be marbles, beans, beads, or other objects. PROCEDURE: Review how to make an "educated guess."  Next, have students estimate how many items they think are in only one of the containers.  Record the prediction.  Then have them count the items and record the information.  Do one container at a time.  After students complete this first part, make a bar graph of their findings.  See the example below to help guide your students.    The margin of error reflects the difference between the actual answer and the projected answer.  Discuss how to determine the margin of error.  Now have students predict and count the other containers.  See if the students' margin of error is reduced.  If so, students are learning that with practice they can estimate with a smaller margin of error.