Using Blackboard to help
students learn concepts in
molecular biology and to assess
their learning
Ethan Hack, School of Biology
Exercises in Stage 2 module
Molecular Biology and Genomics
Aim is to help students understand the structure
of genes.
Two computer practicals, each with two parts:
1. Interpretation of information about genes
from on-line databases.
2. Interpretation of data from (made-up)
experiments on regulation of gene
expression (protein production).
Issues
• Assessment needs to check students’
understanding of concepts.
• “Traditional” method – students write short
answers to structured questions.
• About 200 students.
• Demonstrators do marking but checking is
necessary – time-consuming, challenging to
meet feedback deadlines.
A solution?
• Use Blackboard for assessment.
• Blackboard provides multiple-choice,
multiple-answer, and matching question
types.
– Multiple-choice: as expected.
– Multiple-answer: more than one answer
may be correct.
– Matching: pair items in one column with
items in other column.
• Can these substitute for short answers?
Converting to Blackboard
1. Interpretation of information about genes
from on-line databases – reasonably
straightforward.
2. Interpretation of data from (made-up)
experiments on regulation of gene
expression – complex.
Structure of the exercises
1. Construct a scenario.
2. Give students the opportunity to make
predictions.
3. To test predictions, ask ‘factual’ questions
about data.
4. Interpret the results in relation to the
predictions.
1. The scenario
• Cells produce an enzyme called magpolase.
• Regulation of magpolase production might
take place in several ways.
2. Making predictions: a ‘matching’
question
If magpol regulates
transcription:
If magpol regulates translation:
If magpol regulates stability of
mRNA:
a. The enzyme activity should
change when cells are exposed
to magpol but the mRNA level
should not change.
b. The mRNA level should change
when cells are exposed to
magpol but the enzyme activity
should not change.
c. The change in enzyme activity
when cells are exposed to
magpol should correspond to
the change in mRNA level.
3. ‘Factual’ questions about data
4. Interpret the results in relation to the
predictions
Taking into account your answers to [previous
questions], what stage of gene expression do
you think that magpol regulates?
a. Magpol probably regulates transcription.
b. Magpol probably regulates translation.
c. Magpol probably regulates mRNA stability.
d. There is insufficient evidence to tell what
process magpol regulates.
Administration
Students
• see all questions at once;
• can change answers;
• can interrupt and resume answering the
questions;
• have approximately one week to complete
the work.
Assessment outcomes
• Wide spread of marks.
Distribution of combined marks
Curve is fitted normal distribution
25
Mean
StDev
N
Frequency
20
15
10
5
0
0 10 20 30 40 50 60 70 80 90 100
Mark
56.75
13.84
152
Assessment outcomes
• Weak (but statistically highly significant) correlation
with exam results.
Problems
• Disappointing number of low marks.
• Students can still get the wrong answer for the
right reasons or the right answer for the wrong
reasons.
• Students can go astray and lose a lot of
marks.
• No way to check how students got the answer
(e.g. asking a friend).
• Reading complicated questions on a PC may
cause difficulty and lead to ‘mechanical’
answering.
Improvements to assessment
1. Include some short written answers to check
reasoning.
Example:
Do your conclusions on the position of magpol
response elements (question 15) alter your
conclusion on whether magpol regulates
transcription, translation, or mRNA stability
(question 5)? Explain your reasoning concisely.
2. Manually adjust marks to allow for students
who go astray.
The Blackboard interface makes it fairly efficient to
mark written answers and adjust marks.
Improvements to presentation
1. Provide printed copies of the assessment.
Encourage students to complete these first.
2. Examine wording carefully.
Conclusions
• It is possible to use Blackboard for relatively
complex assessments.
• It is possible to get a wide distribution of
marks with ‘open’ assessments.
• But it is probably best to accept human
involvement in the marking.
• Careful attention to presentation and wording
and refinement of questions are important.
• There is a tension between formative and
summative aims of assessment.