# Blackboard Battles: Test Tool

Blackboard has a feature where you can create tests or surveys. I use this for pre-labs for 3 experiments in 1st year and have done so since 2013/14. I’ve used it for a lab safety quiz as well.  There are various types of question styles you can use, some that can be automatically graded (and are more sophisticated than multiple choice), and some that require manual grading.

I use multiple choice questions to create short formative tests for students to test their understanding. Often these are simpler versions of the MCQs for Peer Instruction or derived from the banks of MCQs that most textbooks seem to come with. Generally they have feedback. For calculations, I generate banks of similar MCQs (inspiration: ViCE2012 http://www.possibilitiesendless.com/2012/09/variety-in-chemistry-education-2012/) via a semi-automated process using excel and ‘concatenate’. This also works for other multiple choice questions where it is easy to define a question stem and variables and just change the variables.

Fill in multiple blanks lends itself to more complex calculations or to balancing equations. For example, I create a table of Beer-Lambert law related calculations with columns of concentration, absorbance, pathlength and molar absorption coefficient and leave one cell blank per row for the student to calculate the appropriate missing value from the others. I have to specify the answer I want and there is little room for rounding errors in this question (compared to calculated numeric styles that I’ll talk about below). It also works for balancing equations – fill in the blank bits  – but some guidance on the right syntax and style need to be given or you need to manually regrade to accommodate some variance. One example is [Co(OH2)6]2+ and [Co(H2O)6]2+: both would probably be marked as correct by a human but not necessarily by automated marking. Also, easier to not require subscripts and superscripts in answers which can create mixed messages about form.

Calculated numeric are brilliant for practice on performing basic calculations like converting between concentration, volume, mass, moles. You can input a range of acceptable values and so can accommodate rounding issues with multi-step calculations. Again a bit of a steer is required for the students as to how many decimal places you want and to state whether units are required. I’ve not done it but I could see a nice question pair with a calculated numeric question giving the value followed by an MCQ to select the appropriate units. Again, the lack of units may create mixed messages but can be handled well.

I use the matching question style for things like determining the products of transition metal reactions. The students get a list of half equations (half in the sense of the reactant half and the product half, not in the electrochemical sense) and match them up. This system can accommodate two or more routes to the same answer, I just forget it can from time to time! I think it’s helpful in the TM reactions, particularly where the students struggle to even think up what the products might be. They can be a bit more deductive in puzzling it out. I’ve found that the reactant half of the equation causes a bit of confusion when it represents several steps in one, for example:

Fe(NO)3(s) + H2O(l) + NaOH(aq) + H2O2(aq)

The students clearly imagine shoving all of that into a test tube when it’s much easier to take each thing in turn and consider it the dissolution of iron nitrate in water followed by formation of iron hydroxide then subsequent oxidation. I may break this type of question down into different steps in the future, I haven’t decided yet because there are several equations, the first two of which cover:

Fe(NO)3(s) + H2O(l)

and

Fe(NO)3(s) + H2O(l) + NaOH(aq)

It might be easier to ensure they appear in that order rather than being randomised by the computer.

For several of these question types, I create banks of questions and students get a random selection. This means that two students doing the pre-lab together are unlikely to get precisely the same questions. This works really well for calculated numeric types where it’s easy to vary volume/moles/mass for the same compound or for complete the blanks styles. For the matching, it requires a completely different set of equations but that’s possible for me because we study several metals in the lab in question.