Sensors Assignment Observations – A2b

Most of you did quite well on the second portion of this database assignment although there was some confusion about what I meant by “comments”.  Here are some observations.

Comments Desired

I asked for comments in two criteria of the grading form.  I was asking you to think about the sensors.  Here are the criteria and what I was looking for.  The comments could be in comment fields, but it was certainly easier to put them in a separate document as many of you did.

• Building Systems asked for “comments on the similarities and differences”  For this I expected you to identify similarities and differences between the sensors for different building systems.  These might include comments on:  size, frequency, cost, life span, sensitivity…..
• Characteristics asked for “comments and tolerances”.  I was hoping for comments on the characteristics of the sensors including your own observations such as whether these made sense to you.  I gave liberal credit here for “tolerance” info and manufacturer’s info, but was hoping for more.
• Overall asked for “Exceptional work with great thought”.  To get full credit here you needed to explain your thought process and any conclusions you reached about the assignment as a whole.

MS Access Comments

So long as you had a working database you got almost all credit.  To get credit for “Explores capabilities of database including reporting and formatting” you had to demonstrate going beyond what I created in the demo videos.

I offer the following observations about using Access itself:

• A number of you created relationship links that would cause difficulties in practice.  That’s not suprising when getting started and I didn’t deduct for it.
• The “measurements” table in my video is an example of a ‘trick’ often used in DB design.  If you have (in our world) a bunch of physical things that you want to use together it’s often best to create a new table (measurements in my case) that is an abstract thing that relates to the physical things you’re interested in.
• In real situations you may often want to use one table in multiple relationships.  Access handles that best by creating multiple “instances” of that table.  If you’re interested I can explain it further.
• A nice technique for documenting a table (or writing general comments) is to create a “Documentation” table that isn’t linked to others and has fields for writing comments.

Jim Mitchell