PSYCH 210 1st Edition Lecture 2Outline of Last Lecture I. Descriptive vs. Inferential StatisticsII. Populations and Samplesa. Random SamplingIII. Terminology and Notationa. Parameters and StatisticsIV. Types of Variablesa. Independent Variablesb. Dependent Variablesc. Attribute Variablesd. Random Assignment TestOutline of Current Lecture I. Ways of Using Variables in Researcha. Correlational MethodII. Scales of Measurementa. Nominalb. Ordinalc. Intervald. Ratio ScaleThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Discrete vs. Continuous DataIV. Summation NotationCurrent LectureI. Ways of Using Variables in Researcha. Correlational Methodi. Relationship between two Dependent Variablesii. Ex) Mental Fitness and Number of Word Games played1. Correlation does not mean causation!a. There could be causality in the relationship, but we just can’t discern what it isb. Experimental Methodi. One Independent Variable, One Dependent Variable ii. Ex) Type of Audience 1. True Independent Variable >>> this makes it experimental!c. Quasi-Experimental Methodi. One Attribute Variable, One Dependent Variableii. Ex) Sex of Dog1. Attribute Variable (cannot randomly assign) >>> quasi-experimentala. Essentially back to Correlational Methodb. Only difference:i. Correlational = continuous dataii. Quasi-Experimental = discrete dataII. Scales of Measurementa. Scales consider different characteristics of numbersb. The type of scales used affect the statistics you can calculatec. Types of Scales:i. Nominal1. Categorize, name or label2. Ex) 1 = male 2 = female** 1&2 = Nominal Data **3. Arbitrary assignment of numbers (i.e. Numbers themselves have no meaningii. Ordinal1. Still categorize2. *Rank Order3. Ex) Race Results:35s --- 1st1st, 2nd and 3rd are Ordinal Data (not the actual data they represent)37s --- 2nd53s --- 3rd4. Assignment does matter5. Do not have equal intervalsiii. Interval1. Category2. Rank Order3. *Equal Intervals4. Ex) °F °F26° 25°27° 39°28° 106°5. Do NOT have an absolute zeroa. Absolute Zero Def: Absenceof anything to be measureat 0i. 0° is still a temperatureiv. Ratio Scale1. Categorical2. Order3. Equal Intervals4. *Absolute Zero5. Ex) Time (s)36s37s38s6. Ex) Length, Percentagev. For the future: Nominal and Ordinal are nonparametric statistics, Interval and Ratio are parametric statisticsIII. Discrete vs. Continuous Dataa. Discrete Def: separate, indivisible categoriesi. Ex) # of faults1, 2, 3, 4, etc. (NOT 1.5, 2.75, etc.)b. Continuous Def: Able to take on an infinite number of valuesi. Ex) Continuous: Course TimeInfinite number of possible resultsc. The type of data you have will affect the statistical analyses and graphing you used. Discrete data have apparent limitsi. Def: Limit is the same as numerical valuee. Continuous data have apparent AND Real Limitsi. Calculating Real Limit1. Determine unit of measurement, then divide in halfBoth sets are still Equal Interval because Degrees represent the physical quality of temp., which is the same from one degree to the next2. The real Limits are ½ a unit below to ½ a unit above the actual numerical valueii. Ex) Value – 55 sec Unit – 1 sec 54.5 --------------55.5 Real Limitiii. Ex) Value – 55.964 Unit – 0.001 sec ½ = .0005 sec LRL = 55.9635, URL = 55.9645iv. General Guideline for Class: Don’t round less than 2 decimal points and try not to round until the end of the problemIV. Summation Notationa. Handout of Common Summation Formulas for Statisticsb. Rule 1: Format of Summation Notationi. ii. ‘The sum of X as i goes from 1 to N’iii. Left of Equation: Condensed Notationiv. Right of Equation: Extended/Expanded Notationc. Rule 2: Adding the Sums of two Variablesi. Σ(X+Y) = ΣX + ΣYii. Left of Equation: Add X & Y, then sum those additionsiii. Right of Equation: Sum X, Sum Y, add the 2 summations togetherd. Rule 3: Multiplying each variable by a constanti. Σ(CX) = C ΣXii. Left of Equation: Multiply each value by constant, sum secondiii. Right of Equation: Sum first, multiply constant seconde. Rule 4: Adding up all the Constantsi. ΣC = NCii. N = number of valuesiii. Multiply total number of values by the constant f. Rule 5:i. ΣXi2 = X12+X22+X32+…XN2ii. Square first, sum secondLower Real Limit (LRL) = 54.5Upper Real Limit (URL) = 55.5NΣ Xi = X1+X2+X3+…XNi=1g. Rule 6:i. (ΣXi)2=(X1+X2+X3+…XN)2ii. Sum first, square