Index 381

smoking, 296–298, 334–335

smoothing fraction, 289–290

Social Science Statistics, 170

software

for data collection, 105–110, 241

evolution of, 54

introduction to, 8

for logistic regression, 256–257

for power calculations, 47

for straight-line regression, 217

types of, 54–60

variables in, 18

Spearman Rank Correlation test, 47–49

specificity, 185–186, 262–264

spot-checking, 109

SPSS (Statistical Package for the Social Sciences),

54–58

SQL (Structured Query Language), 110

square root, 332

square root law, 131

squaring, 332

SRS (simple random samples), 80–81

s-shaped relationship, 214, 252–256

SSQ (sum of squares), 155, 215–216, 234

standard deviation (SD), 119, 123, 143, 222

standard error (SE)

calculating, 147–148, 179–180

of coefficients, 225–226, 340

compared to confidence intervals, 130–131

description of, 38, 129, 163, 242

in a fraction, 41

statistic, definition of, 40

Statistical Analysis Plan (SAP), 70

Statistical Analysis System (SAS), 54–56, 58, 110

statistical distributions, 13

statistical estimation theory, 10, 37–39

statistical inference, 10, 37

Statistical Package for the Social Science (SPSS),

54–58

statistical tests, 8, 40–41, 44, 47–49.See also tests

statistically rare, 93

Statistics For Dummies (Rumsey), 2, 29

Statistics II For Dummies (Rumsey), 29

StatPages, 158, 190, 282

stepped line charts, 312–313

stepwise selection, 195

storage modes, 107

straight-line regression

basics of, 215–216

disadvantages of, 229–231

evaluating, 220–224

using, 216–220

when to use, 213–215

stratified samples, 81–82

strong linear relationship, 214

Structured Query Language (SQL), 110

student t distribution, 357–358

student t test, 41–42, 47–49, 142–152, 362–363

student t value, 226

study design, 2, 7, 14, 88–90

study protocol, 68–71

study rationale, 69

study title, 69

subtraction, 18–19

sum, 27

sum of squares (SSQ), 155, 215–216, 234

summarizing data

categorical, 112–114

numerical, 114–123

survival, 302–316

summary statistics, 111

surveillance, 89–90

survival analysis, 13, 68, 301

survival curve shapes, 329–330

survival data, 208, 301–306, 337, 343

survival rate, 305, 364

survival regression

concepts of, 329–335

definition of, 210

evaluating, 337–343

sample size for, 346–347

using, 335–336

when to use, 328–329, 343

survival time, 301–306, 317–325