KIN 4310 1st Edition Lecture 23Outline of Last Lecture I. Dietary Assessment – MethodsII. 24 Hour RecallIII. Food Record/DiaryIV. Unweighed/Estimated Food RecordV. Estimating Food Portion SizesVI. Food Frequency QuestionnairesVII. Diet HistoryVIII. Duplicate Food CollectionIX. SummaryX. DefinitionsXI. Measuring Physical ActivityXII. IntensityXIII. Physical Activity Level (PAL)XIV. Methods to Assess PAXV. AccelerometersXVI. Heart Rate MonitorsXVII. Direct ObservationXVIII. PedometersXIX. Physical Activity Logs (PALS)These 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.XX. Physical Activity QuestionnairesXXI. SummaryOutline of Current Lecture I. Review QuestionsCurrent LectureI. Review Questionsa. What is a hypothesis?i. A hypothesis is:1. A widely understood fact of nature (is a law)2. An explanation of some observed phenomenon that is supported by large amounts of convincing evidence (is a theory)3. An educated guessb. What is statistics?i. Statistics with an s is not pleural. It is a set of tools used for planning experiments, collecting data, summarizing data, and drawing inferences from data; it is the whole philosophy behind it. We learned specific statistical tests, t test, one sample z test, anova, etc. In addition to those, there are at least 40 or 50 more.c. What is a population? A census? A sample?i. Population – is context specific. It is the collection of all elements to which hypothesis applies.ii. Census – an attempt to collect and measure every individual in a populationiii. Sample – a sub-set of the population that you select to be a part of your studyd. Descriptive Statisticsi. The mean is 9.18ii. The standard deviation is 1.54iii. It is bimodal1. Modes: 10.4 and 12iv. It is positively skewedv. Note: A descriptive statistic is a number that describes the sample like mean, sd, mode, shape of distribution (skewed, symmetrical), etc.e. Inferential Statisticsi. Note: Inferential statistics is what is used to test hypotheses. You have a population from which you draw a sample, and hopefully it is diverse like the population and is representative, then you will do experiment procedure or makeyour observations/measurements, then you will calculate probabilities to determine critical values, p-values, etc. The probabilities allows us to makes these observations.f. Describe 3 different types of samplingi. *Know all 5ii. Systematic, random, cluster, convenience, stratifiedg. Which type of sampling is best?i. Random samplingh. Why?i. It eliminates bias and it generally represents the population but it is not the easiest thing to do because you need a master list and sometimes it isn’t even possible to administrate. i. A group of UH researchers went to a local meal center and invited every fifth meal recipient to participate in a survey. This is an example of a: i. D, systematic samplingj. Name 3 measures of central tendencyi. Mean, median, modek. Name 3 measures of variabilityi. S.d., range, variancel. What is a frequency distribution? How is it usually illustrated?i. You are given a set of numbers, you put it in order, determine how many belong to a certain class/bin. It is a table of numbers. The left column is the range and the x is frequency. There is no overlap in the bins and every piece of data fits intoa bin. *Know the tails of positive and negatively skewed graphs.m. Which of the following statements is true of data with a nominal level of measurement?i. You can calculate a mean (nominal doesn’t use numbers)ii. You cannot generate a frequency distribution (you can generate a frequency distribution but not a histogram because the x axis is not numerical)iii. Paired with another variable, you can use it to calculate a linear correlation coefficient (you need interval or ratio for r)iv. You can calculate a modev. Note: a nominal level of measurement means in name only. It is not ordinal so you cant put measurements in order. With a histogram, the x axis has to be numerical. n. What is an observational study?i. No independent variable. You just go to measure things. You don’t want to influence what you’re measuring at all. Good for helping to describe samples.o. What is an experimental study?i. 2 characteristics: the variable and you can draw a causal inference. A causes B can only be done with an experiment (not an observation)p. What is an independent variable? A dependent variable?i. Independent variable – variable in experiment that investigators controlii. Dependent variable – all things that you measure, the output.q. What is a longitudinal study?i. A study where you look at the changes over time. Like a weight loss study.r. What is a correlation?i. An association with the general population. It is not a causation. The variables are related to each other. s. What is represented by the linear correlation coefficient, r?i. It represents strength and direction of correlation.t. Interpret the following:i. rxy = 0.711. Pretty moderate to strong correlation between x and yii. rxy2 = 0.501. r2 is the correlation of determination. A number from 0 and 1 that is explained by the relationship to the other variable. This means that 50% of the variance in x is explained by y.iii. rxy2 = 11. All of the variance in x is explained y its relationship with y. It’s the perfect correlation. But you don’t know if it is positive or negative. Just that if you know x, you can predict y if you know the correlation between the two.u. The scatter plot on the previous slide showed:i. B, a weak positive correlationv. What is reliability?i. Reliability and validity are properties that describe different measuring tools or instruments. Reliability is the observation made using instrument will be close to the true score. Anything between observation score and true score is error.w. Define 3 kinds of reliability.i. There is 4: test-retest, interrater, parallel forms, internal consistencyx. What is validity?i. Has to do with how you are applying them like the context. Meaningful, useful, and appropriate.y. Define 3 kinds of validity.i. Content, criterion, and construct.z. The Physical Fitness Test recognizes students for their level of physical fitness in 5 events:curl-ups, shuttle run, endurance run, push-ups, and V-sit. Is a child who scores well in one event likely to score well in the other four events? This is a question of:i. B, internal consistency