I had a question on dealing with ambiguous data. IF at the start of the project, a lot of ambiguous data is present how would you zero in on a particular data?
Ask a subject matter expert or experts for their opinion on which method would be the best to accomplish the goals of the project. These can even be people from the team itself.
If the question is not one of how to best accomplish the goal, but rather, how to best estimate the schedule dates, use an average of the schedule data each of the methods would yield (e.g. early start, duration, early finish, etc.). If you are leaning towards one method more than the others, you can use a weighted average.
At the very start of the project that is at the planning stage..Now say, A step can be done by 4 methods. Which of these 4 methods should we employ in our project?
In order to plan for these type of scenarios you have to put time on the schedule to discuss the 4 methods and choose the one that will be taken. Maybe you are worried that you still don't have the staff to be able to decide this.
I guess the short answer, in order to deal with ambiguous data you need a plan to plan.
Ambiguous information, or simply the lack of information effects decision making processes. In many situations people are ambiguity averse by nature - many times irrationally so. An example of flawed decision making via ambiguous information in the psychology literature is the disjunct effect. It demonstrates how people fail to evaluate potential paths logically.
To demonstrate, when a person is considering purchasing a software solution that solve a problem the company needs to tackle. The package costs a lot of money. Meanwhile, your company is soon due to get notice whether it needs to pay more tax, or whether it will get paid tax back, but the outcome is as yet known. Most people in that situation are unable to decide whether to purchase the software solution and put off making the decision. When researchers study such scenarios and they remove the ambiguity - i.e. in this example, they would either say that the company will get tax relief, or that they will have to pay more taxes. With that variable known, the decision making is different. What is found is that with unambiguous information, the person typically consistently chooses one option, regardless of the outcome of the other variable (in this case it would be the tax situation). Logic dictates, that it then shouldn't matter if that variable is yet unknown, if it turns out that you would make the same decision regardless.
This is just one example, but it is an unintuitive one and it happens all the time. Very important to be aware of, even if you yourself have carefully and logically come to decisions, the people you work with may appear hesitant or averse to making decisions.
One way to combat this is to write things out and explore possibilities in detail and figure out how ambiguous information and potentialities effects project planning and what reasonable amounts of risk are.
In sum, as a project manager I think it's important to know in what ways ambiguous information may compromise decision making.
For more about the Disjunct effect, look up the research by Shafir (paper called "Uncertainty and the difficulty of thinking through disjunctions" is a good place to start.