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# Re: st: RE: Graphing the median of a list of variables

 From Jeremy Voros To statalist@hsphsun2.harvard.edu Subject Re: st: RE: Graphing the median of a list of variables Date Tue, 27 Apr 2010 14:55:47 -0400

-collapse- looks like it might be the tool I'm looking for. But, the data I have are self-assessments of competency in a variety of areas. The mean increases as the year increases. I'm trying to devise a method of visualizing the responses to all the questions improving over time. Putting the year along the x-axis would require a separate graph line for each question, of which I have approximately 50, which is too many for such a graph.

-grmeanby- is useful too, but it also will only summarize data for a single variable.

I'm thinking if I could turn my column variables into row values I'd be able to get what I want. So I could have a table like so:

|   question   |   median_1999   |   median_2001   |   etc, for each year
|      1       |       2         |       3         |
|      2       |       4         |       5         |

then the line graph would be trivial.

I might need to consider another visualization method.

And thanks for the suggestion on the mean.

-- Jeremy

On Apr 27, 2010, at 2:12 PM, Nick Cox wrote:

> No; I would use -collapse- first.
>
> collapse (p50) question*, by(year)
>
> After that, it's just a -line- plot. I'd put year on the x axis; any
>
> By the way, even though the data are Likert scales, in my experience
> means in practice often do a much better job of summarising level
> (regardless of measurement theory).
>
> Nick
> n.j.cox@durham.ac.uk
>
> Jeremy Voros
>
> Stata newbie here with a question I'm having trouble finding an answer
> for. I would like to create a line graph with variables along the x-axis
> and their median on the y-axis, with a different line for each variable
> based on the cohort year. Here's the details:
>
> My database of likert-scale survey data looks basically like this:
>
> |      id     |     year     |     question1     |      question2     |
> question3     |     etc...
> |      5      |     1999     |         1         |          4         |
> 3         |
> |      5      |     2001     |         3         |          4         |
> 2         |
> |      6      |     1999     |         3         |          5         |
> 4         |
>
>
> So ultimately I'd like a graph with question1, question2...questionX
> along the x-axis, and the median of each variable on the y-axis, with a
> different line for each year.
>
> I feel like it should involve tabstat or reshape somehow, but can't
> manage to work it out. Any help appreciated.
>
>
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