UNIT 3 MEASUREMENT AND DATA PROCESSING TIER 1 & 2

TIER 1 LEARNING GOALS TIER 1 Define random errors Define systematic errors Define absolute uncertainties Define percentage uncertainties Define precision Define accuracy Define significant figures Define bet fit line Define independent variable Define dependent variable Define interpolate Define extrapolate

RANDOM ERRORS - errors that has an equal probability of being too high or too low SYSTEMATIC ERRORS- errors that result from poor experimental design or procedures ABSOLUTE UNCERTAINTIES- is the size of the range of values in which the "true value" of the measurement probably lies. PERCENTAGE UNCERTAINTIES- interpreted as describing the uncertainty that would result if the measured value had been 100 units. It is calculated by dividing the absolute uncertainty by the measured value times 100.

PRECISION-refers to the closeness of a set of measurements of the same quantity made in the same way ACCURACY- refers to the closeness of a set of measurements to the correct or accepted value of the quantity measured. SIGNIFICANT FIGURES-digits in a measurement up to and including the first uncertain digit

BET FIT LINE-line on a graph that passes as near to as many of the points as possible INDEPENDENT VARIABLE- the variable that is manipulated DEPENDENT VARIABLE-the variable that measured INTERPOLATE-estimating between points on a graph EXTRAPOLATE-estimating beyond points on a graph

EXTRAPOLATE INTERPOLATE

TIER 2 LEARNING GOALS Illustrate examples of random errors Illustrate examples of systematic errors Demonstrate the difference between precision and accuracy  

RANDOM ERRORS THE READABILITY OF THE MEASURING INSTRUMENT THE EFFECTS OF CHANGES IN THE SURROUNDINGS SUCH AS TEMPERATURE VARIATIONS INSUFFICIENT DATA TINY VIBRATIONS, VOLTAGE FLUCTUATIONS AND AIR CURRENTS INTERFERING WITH MASS MEASUREMENTS

SYSTEMATIC ERRORS MEASURING THE VOLUME OF WATER FROM THE TOP OF THE MENISCUS OVERSHOOTING THE VOLUME OF A LIQUID DELIVERED IN A TITRATION HEAT LOSSES IN AN EXOTHERMIC REACTION NOT ZEROING THE BALANCE POOR LAB TECHNIQUES

High Accuracy High Precision PRECISION AND ACCURACY Low Accuracy High Precision High Accuracy Low Precision High Accuracy High Precision