Teacher Notes
This exercise is designed to help students understand the idea that science is built on evidence that can be observed or deduced from the natural world. We gather evidence through the use of our senses. However, the evidence can be confusing, seemingly conflicting, and apparently random. Data is not always consistent nor even readable. Furthermore, all of the evidence may not be available. This is why scientific explanations are "tentative" explanations of natural phenomena.

In this simulation, there are several independent types of clues that may be used to develop a hypothesis. This illustrates the concept that scientists use a variety of criteria to compare explanations, selecting the better ones. Scientists may even have to connect seemingly unrelated lines of evidence to form tentative hypotheses.

Evidence in science, as in this simulation, is not of equal value. Scientists must learn to discern between useful and useless data. In this simulation, the value of each check is affected by the order in which it is selected, and by the relative importance placed upon it by the various group members. Individuals with strongly held opinions or with strong personalities may have a major effect on their group's opinions. This aspect of the activity illustrates that human values, biases and experiences can deeply influence science.

This lab is open ended. There is not enough information to say with certainty what the storyline is and each new check may create more questions than answers. This is a dynamic of both this lab and science. In addition, the participants should recognize that not everyone reaches the same conclusion when observing the same data.

Finally, this simulation encourages participants to equate the solving of a mystery with the search for scientific explanations. At the same time, this simulation reinforces the collaborative nature of science: scientists often work together to solve problems.

Procedure
1. Arrange students into groups (four works well). Each group is given an envelope containing checks written by fictitious characters in a fictitious scenario

2. After reading the Lab Introduction, each team draws four checks from the envelope at random. Using the information on the checks, each group attempts to determine the circumstances that surrounded the writing of the checks. In other words, each group tries to come up with a storyline for the fictitious character(s) based on the information on the checks. This leads them to formulate an original tentative "hypothesis" (=storyline).

3. After the teams appear to have exhausted their ideas with the first four checks, instruct them to select four more checks from the envelope. If you like, you can contrive a situation in which students are detectives using some checks found as partial evidence in some sort of crime; after a period of time, some more checks are found. Observe the groups for insights as to how the new information affects their old hypothesis. Once again, allow each group to work until it appears that most have exhausted their individual lines of thought.

4. Each team should draw two more checks and proceed as before. After a few minutes, suggest that the different groups collaborate by sharing their information. The groups should realize that others may have one or two different pieces of data. Unused checks must stay in envelope (in nature, we never have ALL of the desired info.)

5. At the conclusion of this "share time", ask each group to select its strongest hypothesis (likliest storyline).

6. After giving the groups time to formulate their hypotheses, ask the group spokesperson to stand and report the group-selected hypothesis (storyline) to the class, so that all may hear different conclusions from similar data.

7. Lead a follow-up discussion on the value of collaboration, tentativeness of scientific explanations, the effects of limited data, and the influence of personal biases and experience on their ideas and ultimate selection of a most likely hypothesis. Even if scientists have a strong hypothesis, or explanation of a natural phenomenon, they can never be absolutely sure that new data won't eventually appear and show the explanation to be wrong. You might also use this experience as a springboard to a close look at some of the criteria scientists use to determine which answer (hypothesis) is "best" (closest to reality).