Sunday, February 5, 2012

The Zero Effect

And...we're back. Great to see you all again.

This week, I was building an Excel workbook for teachers. The idea was to create a tool for analyzing student performance on a single assessment. In my case, I was developing for a particular scoring tool (like the example below), but a teacher could make a similar version for a test, allowing one cell per item/point.

At first, this looks like a fairly straightforward affair. I have a list of students down the side. I break down each point of a rubric into the columns in the middle, then have a place to total the points and equate them to a level of performance (e.g., below standard, at standard, above standard) at the end.



Heck, I even added some fancy-schmancy conditional formatting so that the cells with the attribute points would change colour. Note that if more than one point is entered, the cell is highlighted with a border change.

Ooooo. Aahhhh.

WTH, Excel?
But it was too good to last. Excel just had to throw down the gauntlet. Because when I put in the "SUM" formula for the total column, I got a great big zero sitting in the cell---even though there were no numbers in the row to total. I understand that the sum of nothing is nothing...but I don't need the zero there. In fact, as a teacher, I'd prefer that it's blank so I can distinguish between students that haven't done the assessment vs. ones who completed (and bombed) it.

I begged. I pleaded. Please, Excel, let my zeros go. At first, I went in and changed the Options such that zeros didn't show up.
Take that!
Bummer
This sorta fixed things. See, Excel didn't show the zeros, but it acted as if they were still there. This became an issue for the final column. I used a nested IF statement to do the equating (0 - 4 points = below basic, 5 - 6 = basic, 7 - 8 = at standard, 9 - 11 = above standard). And even though no numbers were in any of the preceding columns...and even though I used a "" as the final alternative in the IF statement, Excel didn't care about my personal problem.

So, I set out on a hunt for an answer. Surely I was not the first person in the history of spreadsheets who wanted Excel to not fill its nothingness with zeros. I read many forum posts by people who didn't want zero included for various reasons, but the bottom line was that there was no simple answer to this issue...no magic command to make Excel do my bidding. However, I did find two workarounds that kept invisible zeros at bay.

First dealt with the Total column. I really wanted to leave the option on for showing zero, if a student "earned" it. Originally, I had used the basic SUM function: =SUM(D5:N5). But one YouTube source provided this idea: =IF(COUNT(D5:N5),SUM(D5:N5),""). In other words, tell Excel to count what is in the previous columns...if there's something in them, total them...if not, leave the cell blank. Huzzah!

But this didn't solve the column with the Performance Levels. For this one, I had to use ISBLANK. This function has to be used at the very beginning of a statement. It consists of ISBLANK(value). The "value" refers to a cell. So, by starting my formula with ISBLANK and then following with the nested IF, I knocked out problem #2.

Le Sigh
All was shiny and happy until I got to the point where I wanted to summarize the number of students in each of the performance levels. Here is the formula I was using to total the number of students in Level One: =COUNTIF(P5:P14,"1 = Below Basic")...and the result. I tried ISBLANK at the beginning with the P5:P14 range. It did make the zeros go away, but also kept any other number from appearing. Ditto for the COUNT function at the beginning. And so, my friends, if you have any suggestions, I would love to hear them. (Update: We found the answer! See bottom of post and comments.)

Anyway, here is what the workbook looks like when ready to use:

And here is an example of a completed version:
If you want this sample workbook to play around with, you can download it here. Or, if you want to try before you buy, you can play with it in the window below (it may be easier to click the button on the bottom right to view the workbook full screen, but you won't be able to make edits in that window):




Bonus Round
Yes, Virginia, there are graphs for this spreadsheet. They will autoupdate as you add information. There is one graph for the attribute points, so a teacher can look at the distribution and consider where to place additional instruction. The other graph shows the number of students performing in each category. This one could be useful for comparing pre- and post-assessments. Both would be good starting points for reflection on instructional practice.


Update: I did find an answer (similar to one suggested by a commenter) to the problem above. It is included in the updated spreadsheet. Use the same link to download. Thank you to Jamie for the inspiration!

8 comments:

  1. A hacky fix is to do something like

    =IF(COUNTIF(P5:P14,"1 = Below Basic")=0,"",COUNTIF(P5:P14,"1 = Below Basic"))

    I don't like having to repeat myself in the formula but it's certainly the easiest way to achieve what you're looking for.

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  2. Hmmm...for some reason, that formula isn't working for me. It does keep the zero from showing up when there is nothing to total, but when there is something to total, the box is still blank.

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  3. Huzzah! I used your formula as a starting point and was able to come up with one that would work in the spreadsheet. I used =IF(COUNTIF(P5:P14,"1 = Below Basic"),COUNTIF(P5:P14,"1 = Below Basic"),"")

    Thanks for putting me on the right path!

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  4. When I saw the latest issue of Educational Leadership, "For Each to Excel," I thought somehow you'd commandeered editorship. What a letdown to find out it was all about personalizing the educational experience! :)

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  5. A letdown, I'm sure; but ASCD did give a big shout out to Excel for Educators in its most recent Express issue.

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  6. "A letdown, I'm sure; but ASCD did give a big shout out to Excel for Educators in its most recent Express issue."

    Outstanding! :)

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  7. BTW, What's with all the goobers in my name? Blogger having an issue?

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  8. I don't know why it's freaking about about the ' in your last name. We must have encountered a time warp back to the ASCII days.

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