TABLE 1.
Finalized analytic scoring rubric for analyzing responses to the weight loss item
| Analytic rubric categorya | Criteria | Exemplar student response (key phrases underlined)b |
|---|---|---|
| Correct Molecular Products* | Responses that include correct molecular products in their explanation | “The mass in the body was loss [sic] through losing fat. The fat is converted into glucose, which then becomes energy. The energy then becomes CO2 [sic] and is left the body when breathing.” |
| Carbon Alone* | Responses that do not indicate the molecular form (e.g., CO2) of carbon as a product | “A friend who lost 15 lbs on a diet must have sweat[ed] and exhaled out enough cabon [sic] over the course of his diet to lose 15 lbs of fat.” |
| Molecular Mechanism† | Responses that indicate correct processes (either by name or by description) through which mass is converted into other products | “As his fat stores were broken down (catabolism) to provide energy by cellular respiration, the molecules are broken down. The carbons of these organic molecules is [sic] converted to carbon dioxide and water, which are expelled from the body.” |
| General Metabolism† | Responses that do not completely define or name a correct molecular mechanism (which would fall in the Molecular Mechanisms bin), but that do indicate some a certain degree of (either correct or incorrect) molecular understanding of molecular transformations or processes (either correct or incorrect) | “As the friend metabolized the fat, energy was withdrawn from the fat stores is cataloging the fasts. Simple molecules. These simple molecules were lost as co2 [sic], waste through respiration. A small portion of the fat stores were exited [sic] with other food waste as well.” |
| Matter Converted to Energy | Responses that indicate incorrectly that mass is converted into energy or used up | “The 15 pounds of mass was converted into another source of energy or transferred. The 15 pounds may have also been lost as heat during the diet but in all cases it was not destroyed.” |
| Exhalation | Responses that indicate mass has been released into the air | “The mass is breathed out as carbon dioxide in to [sic] the air.” |
| Excretion | Responses that indicate mass leaves body as nongas waste | “The 15 pounds, through exercise, is lost as heat and water through sweating and exhalation.” |
| How to Lose Weight | Responses that use “common knowledge” about dieting or exercise for weight loss | “It was used by the person to create energy. since they were using more than they were consuming, the matter used to create the energy was pulled from fat stores [ideally, although it could also have been pulled from muscle]. thus the weight went into creating energy [and probably waste too...]” |
aAn asterisk (*) indicates a pair of mutually exclusive categories. A dagger (†) indicates a second pair of mutually exclusive categories.
bAll responses used here and henceforth are included verbatim as the students wrote them, including spelling and capitalization.