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IB Internal Assessment (Lab) Scoring

IB Internal Assessment (Lab) Scoring. DESIGN. DESIGN- Aspect 1 Defining the problem and selecting variables. Examples of scoring: Formulates a focused problem/research question and identifies the relevant variables .

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IB Internal Assessment (Lab) Scoring

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  1. IB Internal Assessment (Lab) Scoring

  2. DESIGN

  3. DESIGN- Aspect 1Defining the problem and selecting variables

  4. Examples of scoring: Formulates a focused problem/research question and identifies the relevant variables. • Background Info: Catalase is an enzyme found in nearly all organisms exposed to oxygen. In our cells it is located in peroxisomes & converts harmful hydrogen peroxide into water & oxygen. 1 QUESTION: What is the effect of altering the pH on the function of catalase? • Is this question focused? (Do you know exactly what the experimenter wants to find out?) • Do you know what levels of pH are going to be tested? • Do you know how the “function” of the enzyme will be determined? SCORE: 1 IMPORTANT! 1 http://en.wikipedia.org/wiki/Catalase

  5. Examples of scoring: Formulates a focused problem/research question and identifies the relevant variables. • Background Info: same as previous slide • QUESTION 2: What is the effect on the rate of oxygen production when hydrogen peroxide and catalase are in a pH environment of 3, 4, 5, 6, 7, and 8? • Is this question focused? (Do you know exactly what the experimenter wants to find out?) • Do you know what levels of pH are going to be tested? • Do you know how the “function” of the enzyme will be determined? SCORE: 2

  6. Examples of scoring: Formulates a focused problem/research question and identifies the relevant variables. • Background Info: The movement of water from areas of high water availability to areas of lower water availability is an important process in all living things. 1 Without it, water would not enter roots cells from the soil nor would water be able to enter the cells of out body. 2 • QUESTION: How do different concentrations affect osmosis? • Is this question focused? (Do you know exactly what the experimenter wants to find out?) • Do you know what is going to be tested? • Do you know how the movement of water will be determined? SCORE: 0 IMPORTANT! 1 http://arbl.cvmbs.colostate.edu/hbooks/cmb/cells/pmemb/osmosis.html 2 -jdldjodgopdgdopd

  7. Examples of scoring: Formulates a focused problem/research question and identifies the relevant variables. • Background Info: The movement of water from areas of high water availability to areas of lower water availability is an important process in all living things. 1 Without it, water would not enter roots cells from the soil nor would water be able to enter the cells of out body. 2 • Your turn! Try writing a focused research question. 1 http://arbl.cvmbs.colostate.edu/hbooks/cmb/cells/pmemb/osmosis.html 2 -jdldjodgopdgdopd

  8. What are variables? • any factor, trait, or condition that can exist in differing amounts or types • An experiment has three kinds of variables: • Independent (IDV)  what is different in order to test the hypothesis/answer the question • Dependent (DV)  the data that is collected • What data are you collecting as you stand at the lab bench? • Controlled  these are all the other things that could be different but you want to keep constant • This ensures that the data you collect allows you to answer the question with confidence

  9. Aspect 1 variables: IDV & DV • QUESTION 2: What is the effect on the rate of oxygen production when hydrogen peroxide and catalase are in a pH environment of 3, 4, 5, 6, 7, and 8? • Independent (IDV): • Levels of pH (3, 4, 5, 6, 7, 8) • Dependent (DV): • Correct DV example: oxygen levels • at time 0 sec, 30 sec, 60 sec, 90 sec, etc. (this is 4 pieces of data) • Incorrect DV example: rate of oxygen production • (you had to do math to get this #

  10. DESIGN- Aspect 2Controlling the Variables

  11. Controlled variables: Aspect 2 • QUESTION 2: What is the effect on the rate of oxygen production when hydrogen peroxide and catalase are in a pH environment of 3, 4, 5, 6, 7, and 8? • Controlled variables: What things can you think of that must be kept constant? Brainstorm with a partner! • Temperature of H2O2 & catalase • Volume/amount of H2O2 & catalase • Source of H2O2 & catalase • Time intervals oxygen readings are taken • Equipment taking the reading • What are things that are not really important to list here? • All IDV levels tested in the same room • Same level of humidity outside • Same amount of light • Same person pouring H2O2 & catalase together

  12. Controlled variables are displayed in a chart & they are included in the procedure. Controlled Variables Chart: Note the use of the metric system!

  13. Practice scoring: IB Sample #2 *Before we look at the controls, let’s score Asp1 while we read. QUESTION (this person embedded their question information in a hypothesis) SCORE: 0 Design asp1 SCORE: ?

  14. Aspect 2: Controlling the variables • What controls do you see in this procedure? • Same person tasting leaf • Same scale used to rate the leaf bitterness • Mouth cleansing procedure for after eating a leaf (crack & water) • What else could/should have been controlled? • Amount of leaf material tasted/tested • Part of the leaf tasted/tested SCORE: 1

  15. Practice scoring: IB Sample #3(Asp 1 first, then Asp 2)

  16. QUESTION (this person embedded their question information in a hypothesis) SCORE: 2 Design asp1 SCORE: ?

  17. Aspect 2: Controlling the variables  Example #3 (pass out procedure handout) • What controls do you see in this procedure? • Test tubes left in water bath for 30 minutes • All apple cube sizes are 1cm3 • Same pH • Same amount of substrate (2 cubes of apple) • Volume of enzyme (pectinase) in each tube • What else is controlled but isn’t listed in the chart? • Total volume in each test tube • Same type of apple • Method of crushing the apple to extract juice • What else could/should have been controlled? • Amount of leaf material tasted/tested • Part of the leaf tasted/tested SCORE: 2

  18. DESIGN- Aspect 3Developing a method for collection of data

  19. “Method,” “Sufficient,” “Relevant”: • Develops a Method: Procedure is complete & explains all necessary steps • Sufficient: • at least 5 different levels of IDV • at least 3 trials at each level of IDV (5 is better) • Relevant: • data collected will actually allow you to answer the question • Ex: If you are trying to measure the amount of bacteria that is on your desk as the day progresses & it is used, you must sanitize the desk before you begin the experiment.

  20. Aspect 3: Develops a method… tannin in leaves experiment (Ex #2) • All steps included that allow another person to complete the experiment? • No; How were the leaves chosen? • Sufficient Data? • No; only 2 leaves (trials) from 3 levels of IDV • Not really quantitative; more qualitative (better if he quantified the amount of light) • Relevant Data • Yes; Student is equating bitter tannin taste to level of light & he is tasting for bitterness. SCORE: 1

  21. Aspect 3: Develops a method… pectinase & pectin (Ex #3) • All steps included that allow another person to complete the experiment? • No; How measure the rate of the reaction? • Sufficient Data? • No; only 1 trial completed for each level of IDV (need at least 3; 5 is better) • Reality of how much juice 2 small apple cubes will yield  small; apparatus says to use 25mL beaker & this would be too big • Relevant Data • Yes SCORE: 1

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