Chapter 5: The Mighty Decision Table: How do I choose
The Decision Latter—start from the bottom of it. Start with the most-simplest method and move up only as necessary. (For this class I will ask you to work your way thought several steps).
Start with the important considerations, bringing in details only when and if needed.
1. Prioritized List: Rank order your alternatives
a. You can do this by either Intuition or actual analysis
b. Analysis breaks the problem into sub problems while intuition takes into account everything at once.
c. Analysis takes longer, requires training…but one isn’t necessarily as good as another.
d. General rule…if decision is important you should do both…. (put intuition away, take a break, come back and do and analysis).
e. If they are not in agreement, either one or both could be wrong…this means that there is an error.
f. Intuition is important, do not confuse it with biased feelings however (flat earth)
2. Reasons versus outcomes.
a. You can choose among a set of alternatives for an alternative that has good consequences or good reasons for being chosen….to justify it to other. (example voting)
Screening is a process that you can use to reduce the number of alternatives that you have by examining each alternative one value at a time.
1. Doesn’t take into account trade offs….so it’s limited in that regard.
2. Rejects alternatives that are clearly unacceptable *BMW Z3 for under 10K*
3. This process is referred too as a non-compensatory decision…as you are not trading off on values.
Screen with the most important value first, then the next…and so forth. If in doubt retain it. When only one alternative remains accept it. If you have more than one alternative, move up the decision ladder.
This is a decision method of choice when your values have overriding importance (money is one of them, book talks about ethical decisions). Also in decisions of low importance, and the other in high cognitive processing cost.
Decision Tables: The idea of a controlled comparison
Describe how one is set up.
Allows for attention to be drawn to cells that are overlooked
Acts as a form of stimulus variation: seeking of dominance of an alternative
Fact table: getting facts is crucial to decision making….
You must be willing to put your values on your alternatives to the test, or this will end up being a self enhancing belief….Real units are superior to percentages.
Plusses and Minuses Value Table
This is the simpliest way to enter values into a value table.
Decision Table. Plus Zero Minus…plus plus
You can put these in in terms of absolute values…a plus is a positive experience..zero neutral experience, negative…negative experience…
Or in relative terms… plus represents an improvement… zero status quo and a minus a worsening from status quoe…
Or highest and lowest value.
This is all we need to screen out irrelevant values and dominated alternatives.
1. attribute is all plusses…all zeros or all minuses…it may be not worth considering…
2. same with too many minuses
3. specifically what we are looking for is dominance, which helps us reject the alternative
Dominance: Alternative B is dominated by Alternative A if there is at least one difference in A’s favor and no difference in B’s Favor.
See example in book for both alternatives and values…
Dominance indicates a superior alternative.
1. If you are unable to identify an alternative that dominates all others, try to create one.
1 to 10 Tables
If it isn’t clear from the pluses and minuses table…then we may need to go this far (which you will have to do for your project)
There are four steps.
1. Rate (usually based upon putting a value upon the fact table, 1 is assumed the worst)
We will talk about local ranges, where 1 is the worst case, and 10 is the best case. However if needed use a Global judgment *worst case situation is zero, where best is 10*
2. Weight the value (The book uses percentages of 1—and a range table)
a. first step is to rank order the attributes
b. try using the magick wishes technique in the book…which attribute would result in the greatest improvement
c. Think about magnitude of impact, duration of impact, probability of impact, and number of people impacted.
d. Distribute a 100 points across the values in a way that it seems to reflect your weights.
e. These weights reflect the full range changes on the attributes, rather than the attribute itself. Is the difference of 10k a year in salary….how important is that range.
Ask our intuition if this ‘feels right’?
3. Multiply down and add across