A writing rubric for “describe” or “explain” questions in Maths and Stats.

Presented by Jeremy Brocklehurst

Examples of describe/explain questions

Compare the distribution of the weights of Sara’s box of Nutty Snack Bars with the expected distribution of the weights if the machine is working properly.

Use statistical terms to explain your answer.

Heights of male and female students from the South African Census @ School Database

Describe features of the distributions comparatively.

And even in Scholarship Calculus:

When given an “explain”, “describe” or “compare and

contrast” task:What are common difficulties that students have?

OSEM – how does it work?

OSEM – how does it work?

What the OSEM writing frame means:O stands for Obvious observations

Write down one thing you notice, then leave a gap, and write down something else you notice. Try to get 3 obvious things.

S is for Specific Under each obvious observation, explain what you mean so that

another person would get it. E is for Evidence Support each observation with numbers or calculations. M is for Meaning: So what? Write down what each of your points tells you about

the original problem/situation. What else could we find out?

What the OSEM writing frame means:O stands for Obvious observations:

Write down one thing you notice, then leave a gap, and write down something else you notice. Try to get 3 obvious things.

S is for Specific: Under each obvious observation, explain what you mean so that

another person would get it. E is for Evidence: Support each observation with numbers or calculations. M is for Meaning: So what? Write down what each of your points tells you about

the original problem/situation. What else could we find out?

What the OSEM writing frame means:O stands for Obvious observations:

Write down one thing you notice, then leave a gap, and write down something else you notice. Try to get 3 obvious things.

S is for Specific: Under each obvious observation, explain what you mean so that

another person would get it. E is for Evidence: Support each observation with numbers or calculations. M is for Meaning: So what? Write down what each of your points tells you about

the original problem/situation. What else could we find out?

What the OSEM writing frame means:O stands for Obvious observations:

Write down one thing you notice, then leave a gap, and write down something else you notice. Try to get 3 obvious things.

S is for Specific: Under each obvious observation, explain what you mean so that

another person would get it. E is for Evidence: Support each observation with numbers or calculations. M is for Meaning: So what? Write down what each of your points tells you about

the original problem/situation. What else could we find out?

What the OSEM writing frame means:O stands for Obvious observations:

Write down one thing you notice, then leave a gap, and write down something else you notice. Try to get 3 obvious things.

S is for Specific: Under each obvious observation, explain what you mean so that

another person would get it. E is for Evidence: Support each observation with numbers or calculations. M is for Meaning: So what? Write down what each of your points tells you about

the original problem/situation. What else could we find out?

What the OSEM writing frame means:O stands for Obvious observations:

Write down one thing you notice, then leave a gap, and write down something else you notice. Try to get 3 obvious things.

S is for Specific: Under each obvious observation, explain what you mean so that

another person would get it. E is for Evidence: Support each observation with numbers or calculations. M is for Meaning: So what? Write down what each of your points tells you about

the original problem/situation. What else could we find out?

140

160

180

200

220

170

210

190

120

110

100

MaleFemale

130

150

MF Heights

200180160140120 170130 190

Female110 150

Male

TallCentimetre

Height: Girls Boys Min: 120 123 LQ: 135 143.75 Med: 149.5 154 UQ: 158 168.5 Max: 245* 193

3. a) Appropriate dot plot drawn b) Appropriate box plot drawn

In the Level 1 Multivariate Data standard (1.10), my students found OSEM a useful guide when writing their conclusions:

1.10 Multivariate – Conclusion

Obvious

1.10 Multivariate – Conclusion

Obvious (Make call: Yes/No)

1.10 Multivariate – Conclusion

Obvious

Specific

1.10 Multivariate – Conclusion

Obvious

Specific (about what? – popns / variable)

1.10 Multivariate – Conclusion

Obvious

Specific

Evidence

1.10 Multivariate – Conclusion

Obvious

Specific

Evidence (justify, support with stats)Meaning

1.10 Multivariate – Conclusion

Obvious

Specific

Evidence (justify, support with stats)Meaning (so what?)-Context (does it make sense etc.?-Sampling variability

1.10 Multivariate – Conclusion

Evidence

Specific

Obvious

Meaning

1.10 Multivariate – Conclusion

Meaning (so what?)-Context (does it make sense etc.?-Sampling variability

Obvious (Make call: Yes/No)

Evidence (justify, support with stats)

Specific (about what? – popns / variable)

1.10 Multivariate – Conclusion

1.10 Multivariate – Conclusion

And even in Level 2 Coordinate Geometry

And even in Level 2 Coordinate Geometry

Specific (labelling)

Evidence (calculations)

Meaning (so what?)

(Relate back to problem)

Obvious observations

(a) Leaflets from us – pay a fixed amount per leaflet

(b) Leaflets delivery co. pays them per bundle of 50 leaflets.If a student delivers more than 300 leaflets they are paid more per bundle.

School students are paid to deliver weekly advertising leaflets to houses.

In groups:

1.Each person has a sheet.

2.Each person fills in one Obvious observation.

3.Then pass it to the next person in your group. They fill in the “Specific” part for your observation AND Write their own Obvious Observation in one of the other boxes. 3.Continue in this way, passing each sheet around until OSEM are completed for all 4 boxes.

4. Then have a go at the Extended Abstract part.

Success Criteria: OSEM

Examples of describe/explain questions

(a) Leaflets from us – pay a fixed amount per leaflet

(b) Leaflets delivery co. pays them per bundle of 50 leaflets.If a student delivers more than 300 leaflets they are paid more per bundle.

School students are paid to deliver weekly advertising leaflets to houses.

Explain how and why the graph in part (b) is different to the

graph in part (a).

(b) Leaflets delivery co. pays them per bundle of 50 leaflets.