Term
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Definition
| A STUDY THAT OBSERVES CHARACTERISTICS OF AN EXISTING POPULATION |
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Definition
| A SAMPLE SELECTED IN A WAY THAT GIVES EVERY DIFFERENT SAMPLE OF SIZE "N" AN EQUAL CHANCE OF BEING SELECTED |
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Term
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Definition
| DIVIDING A POPULATION INTO SUBGROUPS (STRATA) AND THEM TAKING A SEPARATE RANDOM SAMPLE FROM EACH STRATUM [THINK "SOME FROM ALL"] |
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Term
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Definition
| DIVIDING A POPULATION INTO SUBGROUPS (CLUSTERS) AND FORMING A SAMPLE BY RANDOMLY SELECTING CLUSTERS AND INCLUDING ALL INDIVIDUALS OR OBJECTS IN THE SELECTED CLUSTERS IN THE SAMPLE [THINK "ALL FROM SOME"] |
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Term
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Definition
| A SAMPLE SELECTED FROM AN ORDERED ARRANGEMENT OF A PUPULATION BY CHOOSING A STARTING POINT AT RANDOM FROM THE FIRST "K" INDIVIDUALS ON THE LIST AND THEN SELECTING EVERY "KTH" PERSON AFTER THAT |
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Term
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Definition
| A VARIABLE THAT IS RELATED BOTH TO GROUP MEMBERSHIP AND TO THE RESPONSE VARIABLE (AFFECTS THE OUTCOME OF THE EXPERIMENT/OBSERVATIONAL STUDY BUT IS NOT ACCOUNTED FOR) |
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Term
| MEASUREMENT/RESPONSE BIAS |
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Definition
| THE TENDENCY FOR A SAMPLE TO DIFFER FROM THE POPULATION BECAUSE THE METHOD OF OBSERVATION TENDS TO PRODUCE VALUES THAT ARE DIFFERENT FROM THE TRUE VALUE |
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Term
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Definition
| THE TENDENCY FOR A SAMPLE TO DIFFER FROM THE POPULATION BECAUSE OF SYSTEMATIC EXCLUSION OF SOME PART OF THE POPULATION |
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Term
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Definition
| THE TENDENCY FOR A SAMPLE TO DIFFER FROM THE POPULATION BECAUSE MEASUREMENTS ARE NOT OBTAINED FROM ALL INDIVIDUALS SELECTED FOR INCLUSION IN THE SAMPLE |
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Term
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Definition
| A PROCEDURE FOR INVESTIGATING THE EFFECT OF EXPERIMENTAL CONDITIONS ON A RESPONSE VARIABLE (A TREATMENT IS IMPOSED ON THE SUBJECT/OBJECT) |
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Term
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Definition
| THE EXPERIMENTAL CONDITIONS IMPOSED BY THE EXPERIMENTER |
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Term
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Definition
| A VARIABLE THAT IS NOT OF INTEREST IN THE CURRENT STUDY BUT IS THOUGHT TO AFFECT THE RESPONSE VARIABLE |
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Term
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Definition
| HOLDING EXTRANEOUS FACTORS CONSTANT SO THAT THEIR EFFECTS ARE NOT CONFOUNDED WITH THOSE OF THE EXPERIMENTAL CONDITIONS |
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Term
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Definition
| USING EXTRANEOUS FACTORS TO CREATE EXPERIMENTAL GROUPS THAT ARE SIMILAR WITH RESPECT TO THOSE FACTORS TO FILTER OUT THEIR EFFECT |
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Term
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Definition
| RANDOM ASSIGNMENT OF EXPERIMENTAL UNITS TO TREATMENTS OR OF TREATMENTS TO TRIALS |
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Term
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Definition
| MAKING SURE THERE IS AN ADEQUATE NUMBER OF OBSERVATIONS ON EACH EXPERIMENTAL TREATMENT |
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Term
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Definition
| A TREATMENT THAT RESEMBLES THE OTHER TREATMENTS IN AN EXPERIMENT IN ALL APPARENT WAYS BUT THAT HAS NO ACTIVE INGREDIENTS |
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Term
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Definition
| A GROUP THAT RECEIVES NO TREATMENT OR ONE THAT RECEIVES A PLACEBO TREATMENT |
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Term
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Definition
| AN EXPERIMENT IN WHICH THE SUBJECTS DO NOT KNOW WHICH TREATMENT THEY RECEIVED, BUT THE EXPERIMENTERS DO KNOW |
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Term
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Definition
| AN EXPERIMENT IN WHICH NEITHER THE SUBJECTS NOR THE INDIVIDUALS WHO MEASURE THE RESPONSE KNOW WHICH TREATMENT WAS RECEIVED |
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Term
| FREQUENCY VERSUS RELATIVE FREQUENCY |
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Definition
| FREQUENCY IS A COUNT OF HOW MANY, RELATIVE FREQUENCY IS THE PERCENTAGE |
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Term
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Definition
| A MEASUREMENT OF CENTER FOUND BY THE AVERAGE OF THE DATA SAMPLED (DENOTED X-BAR) |
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Term
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Definition
| THE AVERAGE OF THE ENTIRE SET OF SUBJECTS OR POPULATION (DENOTED MU) |
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Term
| GREEK SYMBOLS IN STATISTICS |
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Definition
| ANY GREEK LETTER STANDS FOR A POPULATION PARAMETER |
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Term
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Definition
| ANY ARABIC LETTER (THE ONES YOU ARE READING NOW)STANDS FOR A SAMPLE STATISTIC |
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Term
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Definition
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Term
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Definition
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Definition
| A MEASUREMENT OF CENTER WHERE IT IS THE MIDDLE OF THE DATA SET WHEN THE DATA IS ORDERED FROM LEAST TO GREATEST OR VICE VERSA |
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Term
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Definition
| A MEASURE OF CENTER IN WHICH THE OBSERVATIONS ARE FIRST ORDERED FROM SMALLEST TO LARGEST, THEN ONE OR MORE OBSERVATIONS ARE DELETED FROM EACH END, THEN AVERAGE THE REMAINING NUMBER |
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Term
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Definition
| A MEASUREMENT OF SPREAD, IT IS THE SQUARE-ROOT OF THE VARIANCE |
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Term
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Definition
| A MEASUREMENT OF SPREAD, IT IS THE STANDARD DEVIATION SQUARED |
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Term
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Definition
| THE INTERQUARTILE RANGE, FOUND BY Q3-Q1 |
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Term
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Definition
FOUND BY TAKING Q3+(1.5)IQR
AND Q1-(1.5)IQR. ANY DATA YOU HAVE THAT IS HIGHER THAN THE FIRST OR LOWER THAN THE SECOND IS CALLED AN OUTLIER |
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Term
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Definition
| FOR DATA IN A NORMAL DISTRIBUTION: 68% OF THE DATA IS WITHIN ONE STANDARD DEVIATION OF THE MEAN, 95% WITHIN 2 STANDARD DEVIATIONS AND 99.7% WITHIN 3 STANDARD DEVIATIONS OF THE MEAN |
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Term
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Definition
| A MEASUREMENT THAT TELLS WHERE DATA LIES (IN STANDARD DEVIATION UNITS) FROM THE MEAN (X-MU)/S |
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Term
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Definition
| A SUMMARY OF A DATA SET THAT INCLUDES THE MINIMUM, Q1, THE MEDIAN, Q3 AND THE MAXIMUM |
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Term
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Definition
| A PICTURE THAT CONVEYS INFORMATION ABOUT THE MOST IMPORTANT FEATURES OF A DATA SET: CENTER, SPREAD, EXTENT OF SKEWNESS AND PRESENCE OF OUTLIERS |
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Term
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Definition
| THE HUMP IS ON THE RIGHT, LOW NUMBERS ARE MAKING THE MEAN SMALLER |
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Term
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Definition
| THE HUMP IS ON THE LEFT, HIGH NUMBERS ARE PULLING THE MEAN TO THE RIGHT |
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Term
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Definition
| A PICTURE OF BIVARIATE NUMERICAL DATA (X,Y) |
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Term
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Definition
| THE CORRELATION COEFFICIENT. A MEASURE OF THE EXTENT TO WHICH X AND Y ARE LINEARLY RELATED. 1 AND -1 ARE PERFECT, 0 MEANS NO CORRELATION |
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Term
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Definition
| THE COEFFICIENT OF DETERMINATION. THE PROPORTION OF VARIATION IN Y THAT CAN BE EXPLAINED BY THE LINEAR RELATIONSHIP WITH X |
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Term
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Definition
| A VERTICAL DEVIATION FROM THE ESTIMATED LEAST SQUARE LINE OF REGRESSION. RESID=Y-YHAT |
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Term
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Definition
| WHEN YOU DO SOMETHING MATHEMATICALLY TO THE X, Y, OR X AND Y DATA IN ORDER TO TAKE A CURVED INITIAL SCATTERPLOT AND STRAIGHTEN IT UP. NEEDED BECAUSE r MEANS NOTHING UNLESS YOU HAVE LINEAR OR LINEARIZED DATA |
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