To determine whether schools are increasing the amount of students meeting or(adsbygoogle = window.adsbygoogle || []).push({});

exceeding standards, I obtained a MEAP database reporting the amount of students that

scored in the met or exceed standards range during years 2005-2009, for grades 3-5. I then

graphed the data for using numbers 1 through 5 representing the years since the data

started in the x axis and and the number of students that met or exceeded standards in the y axis.

I am trying to look at progress over time not just as a linear increase, but as something that might speed up then slow down. In particular, any measurement like % at-or-above-basic-proficiency is limited to between 0% and 100% seems to apply here. A simple model for how it might grow in time would be

f(t) = 1 / (1 + b*e^(-a*t) )

-I tried graphing this for simple values like b=1, a=1 on the range t=-2 to t=+2)

Notice it starts out concave-up on the left, and then turns to be concave-down for larger values of t.

I am trying to ask are schools on the concave-up portion of the curve, or the concave-down portion?

I think I could get a partial answer by including a t^2 term in a regression model, then look at the sign of its coefficient--though there are some dangers, like if the coefficient is positive we might be on the downslope of the parabola, with scores decreasing in time! By the way, I am using t=5 meaning the year 2005.

Overall, I am trying to use logistic regression but I am lost on how to try to apply a non linear program of some sort to find a good model.

any advice?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Need advice applying a logistic regression to model school data

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**