We all have heard of the phrase “rule of thumb,” or “rules of thumb.” Generally, this means a widely applicable process that is often used, even if it is not always.
It is often fun to try to find out where phrases like “rule of thumb” come from. In today’s world, if a person wants to find something out, they often “Google it.” (Do you suppose in 100 years someone will write about googling and wonder where that funny word came from?).
At any rate, if you Google “rule of thumb” you will find there are many explanations about where the phrase came from—everything from violence (proper thickness of a stick used to discipline someone or something), to physical measurement (distance between the base of the thumbnail and the first joint is an inch), to wind measurement (raising a wet thumb into the air), or to setting a table (in order set a row of plates one places the thumb on the edge of the table and extends it).
My personal favorite is how brewers use of “rule of thumb.” For makers of Pete’s Wicked Ale, the phrase was attributed to the practice of dipping a thumb in the ale to determine if the beer wort had cooled to the proper temperature for adding yeast.
Distance education is beginning to develop its “rules of thumb,” also. It may be a sign that not enough research is being conducted in the field—but still, rules of thumb do have a certain amount of value when decisions need to be made. Several DeRoTs are being applied by distance educators. (A DeRoT is a Distance Education Rule of Thumb.)
DeRoT 1: One instructor can be responsible for 2-4 distance-delivered courses at a time.
DeRoT 2: A full-time student can successfully participate in 4-6 online courses at one time. On the other hand, students working full-time should not enroll in more than 2, possibly 3 online courses at one time.
DeRoT 3: A three-credit college course, taught at a distance should require students to commit about 8-10 hours per week during a 15-week term.
DeRoT 4: Instructors facilitating threaded discussions should make about 1 posting for every 4 student postings early in a course and gradually reduce postings to about 1 in 10 near the end of the course, as students take on more responsibility for their own learning.
DeRoT 5: Threaded discussions, when graded, are valued more highly by students. A student should make at a minimum at least three postings for each threaded discussion question—one in direct response to the question, one posting in response to another student’s posting, and one in response to what other students have posted in order to build a thread.
DeRoT 6: One instructor, working alone teaching an online class, should have about 20 students, give or take five (actually, this rule of thumb is supported by research reported by Anymir Orellana in volume 7, issue 3 of the Quarterly Review of Distance Education).
Send us your DROTs; certainly there are others. Then, let us get someone to conduct research to move from the rules of thumb practiced by crafts, to the research and theory supporting best practices used by professions.
And finally, an important “rule of thumb” for column writers is to keep it short!
RULES OF THUMB NEED TO BE VALIDATED BY RESEARCH.
