Cost-Benefit examples
Cost-Benefit weighs what one option costs against what it gains, then gives a verdict: yes, no, yes under a named condition, or yes to a cheaper version.
These are fictional teaching examples, not accounts of real events.
Example 1
Should our club buy its own projector?
Owning a projector would end the trips we make to borrow one: we borrow twice a month, and each loan means collecting it the day before and returning it the day after. We could also set up whenever we liked.
It would cost about £350 once, and someone would need to store it and look after the cables.
Against nearly fifty trips a year, a one-off £350 and a cupboard shelf are a small price, so I would buy it and ask the member who lives nearest the hall to store it.
How the answer works
- Benefits
- Explain what the option gains, stated plainly when known.
- Costs
- Name the money, time, effort, risk or other things given up, and who carries them.
- Conclusion
- Weigh the two sides and give a verdict.
Why it works: Benefits come first, and they are known because the loans already happen. The conclusion weighs the trips against the price and the storage job, gives a clear yes and names who carries the cost.
Example 2
Is an evening class worth adding to your schedule?
The class would take every Wednesday evening plus an hour of travel, and the fee is £180 for the term. Wednesday is also the only evening I see my brother, who lives across town.
It would give me a tutor’s feedback on my Spanish, especially on the grammar I keep getting wrong. But I already get most of that at the free conversation group in the library on Saturdays, where two retired teachers correct us.
The class would cost me a lot for a small extra gain, so I would not sign up this term.
How the answer works
- Costs
- Name the money, time, effort, risk or other things given up, and who carries them.
- Benefits
- Say what the option gains that you do not already get elsewhere.
- Conclusion
- Weigh the two sides and give a verdict: yes, no, yes under a named condition, or yes to a cheaper version.
Why it works: The costs include time with family as well as the fee. The benefit is real but mostly available for free, so the conclusion gives a clear no.
Example 3
Is a longer route worth taking today?
The longer route adds about an hour and may leave less daylight for the walk back, and two of us are already tired after this morning’s climb.
It includes the viewpoint we came to see and avoids repeating yesterday’s path along the road.
The viewpoint is the reason for the trip, so it is worth more than an easy afternoon, but not worth walking back in the dark. I would take it only if we can reach the marked junction by three, with enough daylight left to turn back; otherwise I would save it for tomorrow.
How the answer works
- Costs
- Name the money, time, effort, risk or other things given up, and who carries them.
- Benefits
- Explain what the option gains, stated plainly when known and as possible when untested.
- Conclusion
- Weigh the two sides and give a verdict: yes, no, yes under a named condition, or yes to a cheaper version.
Why it works: The conclusion says which side weighs more, then gives a conditional verdict that names its condition: reaching the junction in time. The condition fits because daylight is the one thing still unknown.
What makes the difference?
The same kind of answer can sound complete while leaving an important part unclear.
Should we buy a shared printer?
Not quite
It would make printing convenient and save trips to the copy shop. We should buy it.
Only benefits are given; the price, ink, upkeep and how often we would print are left out. The conclusion cannot show whether convenience is worth the ongoing commitment.
Make it clearer
A shared printer would cost about £200, plus ink, and someone would need to clear jams and reorder supplies.
It would save our weekly trip to the copy shop, where we spend about £5 a week, roughly £250 a year.
Even with ink, the printer pays for itself in about a year, so I would buy it and name one person to look after it.