studying the lorax with feedback loops - Creative Learning Exchange

4. Next, ask students to identify anelement around the circle that changesquantitatively in the story and causesanother element to change. Draw anarrow from the cause to the effect. Youmay label the direction of the changeby putting a + or – sign near the arrowhead. Use a + sign when the change isin the same direction and a – signwhen the change is in the oppositedirection.In the example below, the link from“Thneeds produced” to “Profits” is +because producing thneeds adds toprofits. The link from “Trees cut” to“Truffula trees” is – because cuttingtrees reduces the number of trees.TreescutProfitsFactorysize+Truffula Trees–The Lorax’sangerStudents may be confused at first when using + and – because thesigns do not always mean more and less. In the link between“thneeds produced” and “profits,” when production goes down,profits go down also. That’s still a positive (+) causal relationshipbecause the elements move in the same direction. When the elementsmove in opposite directions, the causal relationship is negative (–).A trickier example is births and population. Even when the number ofbirths decreases, “births” to “population” is a positive (+) causalrelationship, since any birth increases the population. Both elementsmove in the same direction.One or two examples should beenough to get students started. Havethem work in teams as each studentdraws his or her own connections.EnvironmentalqualityOnce-ler’sgreedSample of elements around a connection circle, with a few arrowsfrom cause to effectPage 3ThneedsproducedAnimalpopulation5. After students have had a short timeto work in teams, bring the classtogether to share some of the connections.The circles may look clutteredwith arrows at this point. (See PartialDiagram on next page.) Ask if studentscan trace a path so that they canstart at one element, travel along thearrows to at least one other element,and return to the starting point.6. Instruct students to trace over thepathways using highlighting pens orcolored pencils.7. Have them copy the pathways theyhave traced onto a separate page,drawing them as loops. Chooserepresentatives to draw these loops onthe board or on overhead transparenciesin order to share them with theclass. Name the loops for reference.Students should gain insight as theylook at loops and find leverage pointswithin the story.Elements around the circle witharrows in only one direction (comingin only or going out only) indicate thatstudents have not identified feedbackloops containing that element. Insome cases, the element is not centralto the story, or the informationavailable doesn’t tell us enough tomake another connection. Sometimesstudents need to add an element to thecircle to complete a loop.