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A Mini-Lesson


The Checks Lab

Original version for ENSI '92 by
Steve Randak

ALSO, see the NEW
"E-Mail Lab" version under

This Version by Judy Loundagin

Nature of Science

Social Context

Processes of Science

We now have a textbook for students on the nature of science. It's intended to replace, or supplement, the inadequate first chapter of your text. It's designed to coordinate and help sequence several of the nature of science (NOS) lessons on the ENSI site. It is targeted to students in any science class, grades 7-10 (or beyond). It helps to satisfy virtually all the new NOS standards in NGSS and Common Core. If you've used any of ENSI's NOS lessons, you already know how powerful they are. This new book addresses most of the common misconceptions about NOS. It also provides information about the differences between good science, poor science, and pseudoscience. It offers clues for recognizing those differences, and opportunities to practice using those clues. "What's this magic book I've been waiting for all my life?" It's called Science Surprises: Exploring the Nature of Science. "Tell me more - like where can I see this book?" Say no more. It's available as an eBook, published with Smashwords. Click Here to get more information and a link to sample (and purchase) the new eBook Science Surprises.

See New Scientific Argumentation Information

SEE the NEW "Phantom Tube" Illusion

And See New "3D" Mystery Tubes

And The Data Dilemma lesson


Each team has an envelope containing a series of personal bank checks. A few are removed at a time, and the team attempts each time to construct a plausible scenario that involves those checks. With each subsequent removal of checks, appropriate revision of the scenario is done. Final scenarios are compared by the class. Class discussion is designed to show how the available evidence, along with human values, experiences and biases, influence observation and interpretation, even in science. Scientific argumentation (requiring evidence for all claims) is encouraged, in compliance with the new NGSS and Common Core Standards.

This is one of the few nature-of-science lessons that has a biological connection. This is also one of the few lessons that model the "historical" sciences, e.g., geology, paleontology, astronomy, forensic science, and evolutionary studies (where one uses clues - rather than experimentation - to infer past events).


1. Scientific knowledge is uncertain, tentative and subject to revision.

2. Scientific explanations and interpretations can neither be proven nor disproven with certainty.

3. Scientists use a variety of criteria to compare explanations and select the better ones.

4. Human values deeply influence science (its terminology, the questions asked, and the criteria used for choosing among theories).

5. Scientists can study events of the past for which there are no witnesses available, by proposing plausible explanations, then testing those ideas by looking for clues expected due to a proposed explanation.

6. Scientific argumentation requires that all claims be supported and justified by material evidence. This is an important part of all good science.


1. A series of checks in an envelope (1 envelope per team)
TO DOWNLOAD THE CHECKS (Three sets: A, B, and C), scroll down to the "TEACHING STRATEGY" section (below), then to the HIGH RESOLUTION CHECKS.

The following items are PDF files, and can be downloaded by clicking on its title; to return here, press the "Back" button on your browser:

2. Student Information Sheet (Optional. Usually works better if teacher calls for all teams to “Pull X checks,” all about the same time, so all teams are about together.)

3. Student Worksheet (one for each student)

4. Teacher Notes

5. Overhead Instructions (2nd version: says "...pull 3 checks...")


1. A series of checks in an envelope (1 envelope per team)

2. (optional) Student Information Sheet for each team

3. (optional) Worksheet for tentative explanations and questions to answer.

































































































Mystery Tubes image

Before Doing this lab, consider doing the NEW High-Tech Version: The E-Mail Lab. (Details below under EXTENSIONS AND VARIATIONS.

1. Because this lesson provides an excellent opportunity to understand important elements of the Nature of Science , be sure to read our General Background Information, with our Rationale and our Approach, and tips for Presenting the lessons for maximum effect and Dispelling some of the popular myths about science.

2. In any of the discussions expected with the class, select a few key items (important concepts) that lend themselves to interpretation, and introduce class to the Think-Pair-Share (TPS) routine dealing with those items. This is how "Active Learning" is done.

3. Learn about Scientific Argumentation, and how that's done. This is an important component of the latest NGSS and Common Core Standards. Then...

4. Look over the Additional Teaching Tips for this lab. Several important issues to address.

5. Sample Scenario That Focuses on How This Lesson Models the Approach to "Historical" Sciences: See excellent article by Dr. Laura Henriques "Theoretically Speaking. "The Checks Lab is one of the few interactive lessons (along with various forensic lessons) that illustrates how science deals with problems of the past, events not experienced by available witnesses (sometimes called "historical" sciences, like astronomy, geology, paleontology and evolution science), nor open to repetition.  This is in striking contrast to most investigative experiences found in textbooks and adhering to an overemphasis on "The Scientific Method," giving the impression that that is the only way science is done.  Be sure to provide your students with this information while doing the Checks Lab (since this important process of science is usually ignored in textbooks).

6. TIMING: This lesson is best used in your Nature of Science unit, preferably at the beginning of your course. If you used something else to convey the concepts listed above, then this lesson could be done later in the year as a little "something different" break, to reinforce those concepts.

7. MATERIALS PREP: All materials are available in PDF format. Just click on the appropriate items in bold print below to reach the PDF pages; press the "Back" button on your browser to return to this lesson page.


We have TWO VERSIONS of this activity available here. Judy Loundagin's version is the most complete and structured: (see in Materials Section (above) for Teacher and Students) and TWO SETS OF CHECKS(which you can use in alternate periods). NOTE: that Set A has check numbers, providing an extra clue that might make it easier to figure out sequence of events...:

SET A: 16 checks: 4 checks/sheet; WITH check numbers
note that the printed instructions say "...pull 4 checks..."
  Page 1
Page 2
Page 3
Page 4

SET B: 16 checks: 4 checks/sheet; NO check numbers;
note that the printed instructions say "...pull 4 checks..."

  Page 1
Page 2
Page 3
Page 4

A SECOND VERSION, (developed by Leslie Hays and Paul Loozen), using Overhead, and ONE SET OF CHECKS (Set C):
: 17 checks on 3 sheets; NO check numbers
Note: the overhead instructions for this version say "... pull 3 checks...".
  Page 1
Page 2
Page 3

1. Download and print enough copies of the checks so you will have one set of 16 (or 17) different checks for each team (of 3-4). Cut them apart and put each set (randomly mixed) into an envelope. The entire collection of envelopes can be re-used in each subsequent period, or, if you desire, you can use different sets of checks for each period:
(Set A, Set B, Set C), each in their own collection of envelopes.

2. Run off copies of the Student Information Sheet (Introduction and Directions) and the Worksheet, if desired. You could use one copy of each for each team, or for each student.

This entire lab can be done easily using oral instructions, but the structured material may be the way to go if this is your first experience with this material, especially with the questions used.

3. Follow the Procedure with the Teacher Notes. Item 7 is most vital. Be sure to allow ample time for the discussion. As for the number of checks to draw each time (3-4), use your judgment; try 3 in one period, 4 in another; then do whichever works best.

4. Be sure to point out that this lesson models an important and effective process of science that is NOT experimental - does NOT follow the "Scientific Method" (see item #2 above, under "TEACHING STRATEGY").

5. It shouldn't go unnoticed that some of the checks bring a biological slant to this experience, with checks written to hospitals, mortuaries, AIDS funds, and drunk driving concerns. This makes this one of the few nature-of-science lessons with a biological relevance (a bit of a stretch, but noteworthy)!



  1. During team work, take note of active engagement by each student in each team. Were they asking questions? Were they offering ideas, suggestions? Were they pointing out items on checks that could be helpful?
  2. During class discussion, who participated?
  3. Given components of the checks experience, students will recognize their equivalents in the processes of science. For example, the final explanation, based on items of evidence and student discussion, would be equivalent to --?-- in the process of science. [hypothesis].
  4. Are all possible explanations equally tentative, or are some more tentative than others? [Some more than others].
  5. In the Checks lab, which explanations were most tentative? [The ones based on limited evidence, early in the lab].
  6. Ask why scientific information is tentative. [personal biases, opinions, experiences do influence the explanations suggested. Also, they may not have all the evidence; new evidence could be found at a later time].
  7. Ask what do scientific claims require in order to be considered useful in building a plausible storyline or explanation [evidence].
  8. What features must the “best explanation” have? [It must fit all the evidence (data), be logical, testable, and it must work when applied to new sets of similar data.
  9. Ask why it’s good (and normal) that scientists disagree and scientifically argue about their proposed explanations.


NEW ALTERNATIVE: September 2015:
NEW: The E-Mail Lab: Article by Judith Lederman, et al in The Science Teacher for September 2015, 82(6):57-61. Building on the ENSI Checks Lab (by ENSI teacher Steve Randak, added to by Judy Loundagin), the authors develop a collection of 16 emails from which students attempt to infer past events based on a few samplings of those emails.

They also update the activity with additional suggestions for how it can be done, and has the students engaging in scientific argumentation (focusing on evidence and justifying that evidence). [CAUTION: They use the word "debate," but any kind of formal debate should be avoided; scientific knowledge is not based on formal debates; "discussion" would fit better]. Accommodations for different abilities, grade levels, and needs are suggested, as are possible extensions.

The authors list the 8 Science & Engineering Practices, and the 8 Basic Understandings about NOS found in the NGSS. They also explain how The E-Mail Lab meets 5 of those 8 Science Practices and 4 of those NOS Understandings. The 16 e-mails they developed can be found at <www.nsta.org/highschool/connections.aspx>.
On that NSTA list, scroll down to the September 2015 heading and The E-mail Lab listed there.

1. As suggested, after doing either of these lessons, you could take a closer look at the criteria scientists use to determine the "best" answers to their questions. Click on "Fair Tests: Basic Model for Critical Thinking; How Do Scientists Pick the Best Explanations?", and TRY it!

2. Another activity is built around a structured comparison of the relative strengths of different scientific ideas (theories). Click on "Is Evolution Weak Science, Good Science, or Great Science?", and TRY it!

3. A similar lesson to this Checks Lab is The Great Fossil Find, already on this site. It could be used instead of the Checks Lab, or in addition to it (at a later date, as reinforcement of the concepts, in an appropriate context). The Laetoli Trackway Puzzle lesson also provides an engaging experience, analyzing 3.4 million year old footprints of "Lucy's species. Either of these would be most appropriate for Life Science or Earth Science classes.

4. There are many elements of science in crime scene investigations (CSI), or forensic science, and, as in the Checks Lab, there are many ways to incorporate this exciting field in your Nature of Science efforts. Two lessons on our site that do this well are the Crime Scene Scenario, and Crime Against Plants. Try one. And an excellent online resource for all sorts of ideas and materials can be found on Reddy's Forensic Page: "Forensic Science for High School Students."

5. A nice alternative activity can utilize a sampling of the same set of checks used in this lesson in an interactive online mode on the PBS-Evolution site: "The Check Mystery".

6. MYSTERY BOXES: Try this excellent and very popular lesson which, as presented here, embodies many of the same elements as the Checks Lab. Makes a good alternative to the Checks Lab (or reinforcement of the same features of science).

7. For another type of "Mystery Box", consider the Mystery Tube to add to your NOS Tool Kit. Take a look at the 3-D Molecular Design version (shown at the left). They are about 18 cm (7 in.) long. They come with presentation directions and discussion questions. Specific ways these tubes meet the NGSS are pointed out. Prices and contact information are provided for ordering (use their phone number). Makes a good discrepant event "grabber" or engaging activity with which to begin a class.

8. For another "Mystery Tube" variation, take a look at the Phantom Tubein the Magic Hooey Stick lesson, item #4 under Other Resources. It's available from Flinn Scientific.

9. Also, consider getting The Data Dilemma lesson from 3-D Molecular Design. This engaging lesson models how scientific models are developed, tested and modified with new information. It uses Tangram pieces as examples of “information” used to build a particular shape, as a metaphor for how science works. Instructions are provided along with sample questions for class discussions. Specific ways this lesson meets the NGSS are pointed out. Prices and contact information are provided for ordering (use their phone number). Enough material in one kit for 12 teams. You can do much the same with a jigsaw puzzle, without the picture on the box!

10. JIGSAW PUZZLES: Another useful and engaging metaphor for the processes of science is a jigsaw puzzle. Find a jigsawed picture that reflects some field or concept of science. Have a different puzzle for each class. For lower grades, or a "challenged" class, select a picture that is not too challenging. For middle school or high school, use a more challenging picture (one that will be difficult to project the likely theme or total picture until nearly all pieces are fitted in).

If possible, be able to display the ongoing puzzle on wall (or in glass-front cabinet). At the beginning of the year, have students start putting puzzle pieces in place. Might even be better if you can place all edge pieces, creating a puzzle frame. Each day, another student or team selects and places a new piece (or 2 or 3). As picture progresses, have students predict what they think the picture will be. Perhaps have them put their prediction in a secret ballot box. Check it daily, and keep track of dates and any students who predict accurately.

At some point, ask students if they recognize the elements of scientific problem solving in their on-going processing and development of the picture. How close to  reality (the actual picture on the box) do they get in their early predictions? For realism, remove several puzzle pieces from the collection before they begin, so they never will be able to use them. At some point, ask how is this like the Checks Lab, or the Great Fossil Hunt, or real science. And how is it different?


Some of the ideas in this lesson may have been adapted from earlier, unacknowledged sources without our knowledge. If the reader believes this to be the case, please let us know, and appropriate corrections will be made. Thanks.

1. Original Source: a Social Studies activity source unknown)
2. Adaptation to ENSI version by Steve Randak ( for ENSI '92)
3. Revised version: Leslie Hays & Paul Loozen, for '93 SENSI (set C)
4. Revised version: Judy Loundagin, Oct. '96 (sets A & B)

5. Preliminary approval for ENSIweb by: M. Nickels, C. Nelson, J. Beard: 12/15/97

6. Edited / Revised for ENSIweb by L. Flammer 2/2000
7. Re-edit (removed Low Res checks): Flammer 3/ 2012
8. Updated with Scientific Argumentation: Flammer 7/2013.
9. Updated (including new e-mail version): Flammer 9/2015


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