New rule: As-designed dimension value doesn't establish functional or manufacturing target. Concentricity and symmetry tolerances removed from standard. Surface texture and flaws now included in tolerance zone. Radius tolerance changes: arcs become concentric when center located via dimensions
Measure total space height from bottom to top (rise). Add 6-7 feet for headroom between stair top and ceiling. Divide total rise by 6 or 7 inches to get number of steps. Divide total rise by number of steps to get step height
Rectangle is a quadrilateral with four sides. Opposite sides of a rectangle are equal in length. Perimeter is the total distance around the outside edge
Square meters measure two-dimensional space like fields or floors. Use meter stick or metric tape measure with meters or centimeters. Measure length from corner to corner, including centimeters if needed. Measure width angled 90º from length. Convert centimeters to meters by moving decimal point left
Reliability measures consistency of a measure, while validity indicates accuracy. A measurement can be reliable without being valid, but validity usually indicates reliability. Reliability is easier to assess than validity but more important
Cronbach's alpha measures internal consistency of tests and measures. Named after American psychologist Lee Cronbach. First published in 1951 with additional derivation