Topics that are most forgotten by software developers following their education.

Topics where the difference between question 2 and 1 was negative, indicating that the material was subsequently forgotten, and presumably is not much used on the job. Is the investment in education of this material effective?

**Sample of data from the **1998 Survey of Software Practitioners

Rank |
Topic |
Forgetting since education (Q2-Q1) |
Q1: Knowledge after education |
Q2: Knowledge Now |
% where Q2 -Q1 <= -2 |

1 |
Differential Equations |
-1.2 |
2.7 |
1.6 |
38% |

2 |
Differential and Integral Calculus |
-1.1 |
3.2 |
2.1 |
38% |

3 |
Linear Algebra and Matrices |
-0.8 |
3.1 |
2.3 |
24% |

4 |
Chemistry |
-0.8 |
2.2 |
1.4 |
21% |

5 |
Physics |
-0.7 |
2.7 |
2.1 |
21% |

6 |
Laplace and Fourier Transforms |
-0.6 |
1.8 |
1.2 |
21% |

7 |
Probability and Statistics |
-0.5 |
2.9 |
2.4 |
17% |

8 |
Combinatorics |
-0.4 |
1.7 |
1.4 |
12% |

9 |
Set Theory |
-0.4 |
2.5 |
2.1 |
12% |

10 |
Predicate Logic |
-0.3 |
2.2 |
1.9 |
12% |

11 |
Graph Theory |
-0.2 |
1.9 |
1.7 |
7% |

12 |
Control Theory |
-0.2 |
1.2 |
1.1 |
7% |

13 |
Analog Electronics |
-0.2 |
1.3 |
1.2 |
9% |