9th Grade Performance Task
Developed by: RAND Corporation (RAND)
Stanford University and the Far West Laboratory, 1994

Rate of Cooling Design
Scoring Rubric

#1 (pg. 2)

1.1 Purpose (States any purpose)
The student restates in his or her own words either (1) the purpose of the experiment (for example, "to find the jacket fabric that would keep a person warmest" or (2) what the experiment is trying to determine (for example, "which fabric will keep the water the warmest" or "what are the rates of heat loss") Note: Almost always give credit unless only a conclusion is specified.

#2 (pg. 2)

2.2 Volume

• lists "volume of water" or "amount of water" or
• measurement such as "200 ml" (ml alone also okay)

2.2 Initial temperature of water in can ("water temperature," "temperature," or temperature measurement such as "37 deg. Celsius" also okay)

2.3 Times at which measurements are taken ("time," interval measurement such as "30 sec.," or units such as "seconds also okey)

2.4 Other (Variables must be possible confounding factors - for example, "initial temperature" or "temperature," "depth of thermometer" or "exact temperature of ice water bath." Items copied directly from the materials list are not acceptable.

#3 (pg. 3-4) (For scoring this question, information clearly conveyed in figures, tables, diagrams, etc., in answer to question 3 should be credited.)

3.1 Materials - lists or illustrates 2 or more (any list okay)

3.2 Steps - 2 or more are numberred. Lists any series of at least two numbered steps for procedure ("first, second, etc.," "a, b, etc." okay)

3.3 Rate - takes temperature at specified time intervals or records time for temperature to increase to a certain value for at least one can

• procedure measures temperature as a function of time (e.g. "measure temperature, (after 5 minutes) measure again," "take temperature every 30 seconds") or measures time as a function of temperature (e.g. "write down how long it takes for temperature to decrease 10 degrees") must clearly imply use of a thermometer with statements such as "take temperature," check thermometer," "put thermometer in can...check" ("see how much it heated up" is also okay)
• temperature checked only at the end of a time interval is acceptable only if three tubes are heated and measured simultaneously.

3.4 Fabrics - tests 2 or more

Procedure performed for different fabric-covered cans (general reference okay, for example, "change the fabric" or "do the same with the other fabrics"). Just mentioning three fabrics but measuring none is okay.
(Note on variable measurement and control: The student may choose to add replication trials or trials in which confounding factors are treated as variables (e.g., "use 50 ml of water for the first trial, 100 ml for the second"). Give credit where appropriate for specifying amounts, but do not give credit for using same procedure unless the important variables are also controlled in other trials.)

3.5 Volume - specifies or controls amount of liquid in tube

Procedure must explicitly measure volume or assert that the same amount of water must be used for each fabric trial; responses such as "fill the can with water" are not acceptable.

3.6 Initial temperature specified

• 37 degrees Celsius water used (not "at or above 37 deg. Celsius" or
• "body temperature" water specified

3.7 Uses the same procedure for all fabrics

• same measurement specified for each fabric or
• measurements are made for the first fabric and instructions are to "do the same with the other fabrics."

#4 (pg 5)

4.1 All 3 fabrics labeled on table

4.2 Time (intervals or to criterion)

• at least 2 headings with "sec" or "min" or
• criterion heading (e.g. "temperature after 5 minutes") (unit of time is needed: "start" and "end" not okay)

4.3 Temperature in chart title or heading (can be indicated by title or heading with the words "temperature," "degrees," or "degrees Celsius")

#5 (pg 5)

5.1 Temperature in first blank (degrees, Celsius, or degrees Celsius)
("temperature," "heat" or "5 degrees" not okay)

5.2 Time in second blank (minutes, seconds, or time interval such as "30 seconds")

Rater Answer Form - Rate of Cooling: Design

Rater Name: ________________________

Rater ID Number: _______________

Instructions: Circle the number of points awarded for each question.