Monthly Archives: May 2014

30 is the rule of thumb…

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In a recent post, I said that 30 was the rule of thumb, i.e., 30 cases was the minimum needed in a group to be able to run inferential statistics and get meaningful results.  How do I know, a colleague asked? (Specifically,  “Would you say more about how it takes approximately 30 cases to get meaningful results, or a good place to find out more about that?”) When I was in graduate school, a classmate (who was into theoretical mathematics) showed me the mathematical formula for this rule of thumb. Of course I don’t remember the formula, only the result. So I went looking for the explanation. I found this site. Although my classmate did go into the details of the chi-square distribution and the formula computations, this article doesn’t do that. It even provides an Excel Demo for calculating sample size and verifying this rule of thumb. I am so relieved that there is another source besides my memory.

 

New Topic:

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Survey data

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Had a comment a while back on analyzing survey data…hmm…that is a quandary as most surveys are done on line (see Survey monkey, among others).

If you want to reach a large audience (because your population from which you sampled is large), you will probably use an on-line survey. The on-line survey companies will tabulate the data for you. Can’t guarantee that the tabulations you get will be what you want, or will tell you want you want to know. Typically (in my experience), you can get an Excel file which can be imported into a soft ware program and you can run your own analyses, separate from the on line analyses. Continue reading →

Wednesday’s musings

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I had a comment about last week’s post on Sustainability and Evaluation. I will share it here. I wonder what you readers think of this comment:

In preventive health/health promotion, ‘sustainability’ has generally been used to indicate that the intervention program, or elements of it, or benefits of it, are continued beyond the life of the funded program. It is about extending the value of the investment in a program, beyond the life of the funded program. So it’s about a legacy, about the continuation of things achieved, about leaving things, circumstances or communities better off than when you first arrived (more empowered, more resourceful, more able to continue improvements on their own).

I wonder how that fits with the definitions I provided? Is this a different sustainability? Does it speak to the future generations? Does that include equity and justice? Continue reading →

Sustainability relates to evaluation

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To quote Annie Leonard, the word sustainability “gets thrown around all the time now and it’s not always clear what is intended.” She goes on to talk about the UN World Commission on Environment and Development definition of sustainable development as “…meeting the needs of the current generation without compromising the ability of future generations to meet their own needs.” That is a good definition, I think. Yet it is missing something which (according to Leonard) are equity and justice. Robert Gilman defines sustainability as “…equity over time”. She says (and I agree), quoting the Center for Sustainable Communities, that sustainability “consider(s) the whole instead of the specific. Sustainability emphasizes relationships rather than pieces in isolation.”

Now, given that evaluation to be effective must look at the whole (here is a good example of when the whole is greater than the sum of its parts); and

given that evaluation works to find out information that will benefit both the current and future generations; and

given that evaluation works to determine what difference was made in people’s lives, it seems to me that there is a relationship here that needs to be acknowledged.

A colleague of mine works in youth development and loves the job. My colleague has to determine the value of the program; the program needs to be evaluated. Yet, if the work is only for the program (i.e., the pieces in isolation) not the whole, what good is it that my colleague loves the job? The relationship between the youth involved and the bigger picture is truly more than can probably be captured in any evaluation. Still, the evaluation needs to be planned to consider that, even if the resources are limited (that is the “probably” above).

So yes, evaluation has something to learn from sustainability. Certainly sustainability can learn from evaluation (and economics, and equity, and ecology…).

NEW TOPIC

I’ve been, once again, getting comments about making a difference. I thought I’d post some of those comments (I’ve copied and pasted comments so the spelling is as it appears in the original text):

  • …every blog post makes a difference in a way or in another. You can answer at your questions just seeing how many comments are here, how many people are interested in answering you. I think you are a good person, and everything said by a good person is always a life’s lesson to keep in mind. Thank you for every helpful information, good job!

  • It may be a temporary difference – i.e. limited on the time, but of course that at least for some seconds your writing are touching the life’s of all your readers.

  • Every blog or article makes a difference to those who read it! They might strongly agree or disagree with what the blogger has wrote, making a difference by reafirming there opinion or being outraged that somebody else looks at ideas different to them! Keep writing Molly, you are making people think, which is always good

  • I think the best measure of the effectiveness of a blog are the number of shares it gets, as people that found something useful in it tend to want to share with others.

  • …I have written quite a bit about this topic and challenge that bloggers face and the bottom line is that you really can’t measure the value.  Sure I think asking for responses like you did might help you see a bit of it, but the reality is 99.9% of people will never comment.  As such, we as bloggers have to remember that each pageview is a real person who was on our site and who was impacted by what we wrote!

  •  Blogs are probably the best tool for engaging a customer in todays times.

My question: are blogs engaging readers or are they only outreach, even if the blog is read?

P.S. I also got a lot of comments about my analytics post…for next time.

 

References:

Leonard, A. (2011). Story of Stuff. NY: Free Press.story of stuff (good book–worth the read)

Report of the World Commission on Environment and Development. (1987). NY: UN World Commission on Environment and Development. http://www.un-documents.net/our-common-future.pdf

Gilman, R., Director, Context Institute.

  • He says:  Sustainability is equity over time.  As a value, it refers to giving equal weight in your decisions to the future as well as the present.  You might think of it as extending the Golden Rule through time, so that you do unto future generations (as well as to your present fellow beings) as you would have them do unto you.

Center for Sustainable Communities is quoted in a variety of places: http://sustainablesonoma.org/keyconcepts/sustainability.html; http://isocs-sustainability.wikispaces.com, among others.

  • The entire definition is: Sustainability is part of a trend to…consider the whole instead of the specific. Sustainability emphasizes relationships rather than pieces in isolation…Sustainability is not about regressing to primitive living conditions. It is about understanding our situation, and developing as communities in ways that are equitable, and make sense ecologically and economically.