### Assessment: Preliminary item analysis data for statistics and physical science test one

**MS 150 Statistics**

Test one this term was substantively similar to test one last term permitting a term-on-term item analysis of student performance (fall 2008 versus spring 2009). Overall there was no change in performance as measured by an item analysis. There were, however, changes in performance within specific topic areas. The number correct (corr) refers to the number of students getting that item correct. The fall term had 45 students taking test one, this term the course has 57 students who took test one.

I | s | q | Spring 2009 | corr | perc | Fall 2008number correct | perc | change | |

t01 | 2 | 1 | level of measurement | 33 | 0.58 | 25 | 0.56 | 0.02 | |

t01 | 2 | 2 | sample size | 54 | 0.95 | 40 | 0.89 | 0.06 | |

t01 | 2 | 3 | minimum | 57 | 1.00 | 43 | 0.96 | 0.04 | |

t01 | 2 | 4 | maximum | 57 | 1.00 | 44 | 0.98 | 0.02 | |

t01 | 2 | 5 | range | 56 | 0.98 | 40 | 0.89 | 0.09 | |

t01 | 2 | 6 | midrange | 40 | 0.70 | 36 | 0.80 | -0.10 | |

t01 | 2 | 7 | mode | 53 | 0.93 | 41 | 0.91 | 0.02 | |

t01 | 2 | 8 | median | 44 | 0.77 | 36 | 0.80 | -0.03 | |

t01 | 2 | 9 | mean | 45 | 0.79 | 33 | 0.73 | 0.06 | |

t01 | 2 | 10 | standard deviation | 43 | 0.75 | 35 | 0.78 | -0.02 | |

t01 | 2 | 11 | coefficient of variation | 38 | 0.67 | 30 | 0.67 | 0.00 | |

t01 | 2 | 12 | width | 40 | 0.70 | 36 | 0.80 | -0.10 | |

t01 | 2 | 13 | frequency table | 21 | 0.37 | 28 | 0.62 | -0.25 | |

t01 | 2 | 14 | frequency histogram | 20 | 0.35 | 26 | 0.58 | -0.23 | |

t01 | 2 | 15 | shape of histogram | 38 | 0.67 | 28 | 0.62 | 0.04 | |

t01 | 2 | 16 | inference | 21 | 0.37 | 7 | 0.16 | 0.21 | |

t01 | 2 | 17 | z-score | 20 | 0.35 | 13 | 0.29 | 0.06 | |

t01 | 2 | 18 | inference | 29 | 0.51 | 17 | 0.38 | 0.13 |

Performance fell markedly and significantly on material from section 2.2 of the text, frequency tables and histograms. As a result, this material was reviewed in detail with the students. This material will be retested on the midterm.

The overall success rate of 69% for the spring term is identical to the success rate for the fall term and falls well within the historical range of 65% to 75%.

SC 130 Physical Science

SC 130 Physical Science

Although the tests are not substantively similar term-on-term from fall 2008 to spring 2009, there was overlap in material for test one in the two terms. On overlapping material there was a modest overall gain of 6% as measured by item analysis. Thirty-three students took test one spring 2009, in fall 2008 twenty-eight students took test one.

q | Spring 2009 | corr | perc | Fall 2008 correct | perc | perc | |

1 | plot data | 33 | 1.00 | ||||

2 | inference from graph | 29 | 0.88 | ||||

3 | calculate velocity | 16 | 0.48 | ||||

4 | infer acceleration | 0 | 0.00 | ||||

5 | peripatetic | 20 | 0.61 | 20 | 0.71 | -0.11 | |

6 | list three fundamental qualities | 32 | 0.97 | ||||

7 | list qualities required for motion | 29 | 0.88 | 24 | 0.86 | 0.02 | |

8 | calculate volume | 27 | 0.82 | 23 | 0.82 | 0 | |

9 | calculate density | 20 | 0.61 | 16 | 0.57 | 0.03 | |

10 | inference from result | 22 | 0.67 | 12 | 0.43 | 0.24 | |

11 | inference from graph | 25 | 0.76 | 13 | 0.46 | 0.29 | |

12 | inference from graph | 8 | 0.24 | 9 | 0.32 | -0.08 | |

13 | write an equation from graph | 17 | 0.52 | 16 | 0.57 | -0.06 | |

14 | given x determine y from quadratic | 6 | 0.18 | ||||

15 | calculate mean | 27 | 0.82 | 11 | 0.39 | 0.43 | |

16 | identify outlier error | 25 | 0.76 | 26 | 0.93 | -0.17 |

An encouraging gain was seen in the ability of students to make an inference from material provided on the test. This term marks the first term that the course is working solely from the physical science text I worked on during 2008. The two percent gain in overall performance as measured by the item analysis from a 62% success rate to a 64% success rate is not significant and yet is encouraging.

The specific performance by question on test one provides guidance on areas of student weakness that will be addressed as the course moves forward. Of glaring note is that no student could make the inferential leap that a constant velocity implies a zero acceleration (question number four). This matter was reviewed when the test was returned to the students.

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