CSC302H1 Lecture 23: 2014.04.01
Document Summary
Estimates: in planning, neet to estimate f, n, and t; such that estimated (f ) estimated ( n ) estimated (t , estimates never 100% certain. Ex. feature may be estimated to be 20 ecds. Doesn"t mean it"ll be done in 20 ecds. An estimate = stochastic variable, a quantity whose: three-point estimating provide better estimate than value depends upon unknowns or randomness asking for range. Confidence intervals: confidence intervals for work factor (pdf) W is a stochastic variable, even when its measured. Nneed to describe it by a statistical distribution i. e. the probability of w being within a certain range. Can describe w with a probability density function. X-axis = possible range of the variable. Probability w is between two (a, b) = area under the pdf between (a, b) on the x-axis. Assume work factor is described by normal distribution, mean = 0. 6. Notice: average case (half the time less, half the time more) work factor = 0. 6.
