MATH 105 - Exam 1 (Chap 1-6) Questions With 100% Verified Answers| Graded A+.

Statistics - correct answers a collection of procedures + principles for gaining and analyzing info in order to help people make decisions when faced with uncertainty Sample - correct answers a subset of the population; those studied population - correct answers larger group from which the sample was chosen Observational Study - correct answers observe things about our sample Randomized Experiment - correct answers randomly assign participants to one of various treatment groups; the manipulation is assigned to participants on a random basis ; each of the experimental units has a specified probability of receiving any of the potential treatments Observations and experiments - correct answers used to investigate causal relationships between variables explanatory variable - correct answers what you manipulate or observe changes in response variable - correct answers what changes as a result (outcome) Data - correct answers plural word referring to a collection of numbers or other pieces of info to which meaning has been attached 3 Main Reasons Studies are Conducted - correct answers 1) By gov't/private companies to make wise policy decisions 2) Universities/Institutes paid to ask or answer Qs about the world around us 3) Companies to convince consumers their program or product is better Origins of News Stories - correct answers Academic conferences, scholarly journals, University media office 7 critical components - correct answers 1. Source and funding of research 2. Researchers who had contact w/ participants 3. Individuals or objects studied + how they were selected 4. Measurements made or Qs asked 5. Setting 6. Differences in groups being compared 7. Extent or size of any claimed effects or differences 7 pitfalls when asking questions - correct answers 1. deliberate bias 2. unintentional bias 3. desire to please 4. asking the uninformed 5. unnecessary complexity 6. ordering of questions 7. confidentiality vs. anonymity Deliberate bias - correct answers if a survey is being conducted to support a certain cause, questions are worded in a biased manner Ex) "Do you agree that..." unintentional bias - correct answers Sometimes questions are worded in such a way that the meaning is misinterpreted Ex) If you were to ask ppl what drugs they use, you would need to specify if you mean prescription drugs, illegal drugs, or over-the-counter drugs desire to please - correct answers survey respondents have a desire to please the person who is asking the question Ex) "Do you wash your hands after using the restroom?" asking the uninformed - correct answers ppl don't like to admit they don't know what you're talking about when you ask them a Q on a topic they're unfamiliar with Ex) "Do you agree or disagree with the latest political decisions in Madagascar?" unnecessary complexity - correct answers Qs should be kept simple Ex) "Shouldn't children who have a Body Mass Index (BMI) at or above the 95th percentile not be allowed to spend a lot of time watching television, playing computer games, and listening to music?" ordering of questions - correct answers a previous Q can influence a person's response to a later Q Ex) "Are berries one of the best fruits you can eat? What are your favorite fruits?" confidentiality vs. anonymity - correct answers people sometimes answer questions differently based on the degree to which they believe they are anonymous Ex) "What is your address? How much is your annual salary?" Open question - correct answers a Q in which respondents are allowed to answer in their own words Advantages: respondents are free to say whatever they choose, rather than limiting themselves to the choices provided Disadvantages: responses are difficult to summarize, logical responses might not come to mind and wording of the Q might unintentionally exclude answers that would've been appealing had they been included in a list of choices Closed question - correct answers a Q in which respondents are given a list of alternatives from which to choose their answer Advantages: easier to administer + analyze, don't have to come up with answer on your own Disadvantages: may limit options bc respondents will rarely volunteer a choice that isn't presented, even if there is an option to choose "other", respondents tend to choose option given later in the list Pilot study - correct answers a small group of ppl are asked the Qs in open form (the "pilot survey") & their responses are used to create the choices for the closed form most common method for measuring emotions - correct answers to have respondents read statements + determine the extent to which they agree with the statement categorical variables - correct answers those we can place into a category but that may not have any logical ordering ordinal variable - correct answers if the possible categories have a natural ordering Nominal variables - correct answers categorical variables for which the categories do not have a natural ordering Measurement variables - correct answers (aka quantitative variables) those for which we can record a numerical value and then order respondents according to those values -- also called quantitative variables. Sometimes we further distinguish between interval (can talk about differences but not ratios) versus ratio (has a meaningful zero). interval variable - correct answers a measurement variable in which it makes sense to talk about differences, but not about ratios; a variable used for observations that have numbers as their values; the distance (or interval) between pairs of consecutive numbers is assumed to be equal Ratio variable - correct answers a meaningful variable of zero, and it makes sense to talk about the ratio of one value to another Ex) Pulse rate; pulse rate of 60 before exercise + 120 after exercise, you can say your pulse rate doubled during exercise discrete variable - correct answers one for which you could actually count the possible responses Ex) Measure # of car accidents continuous variable - correct answers can be anything within a given interval Ex) Age falls on a continuum valid measurement - correct answers one that actually measures what it claims to measure reliable measurement - correct answers one that will give you or anyone else approximately the same result time after time when taken on the same object or individual biased measurement - correct answers a measurement that is systematically off the mark in the same direction Variability - correct answers they are likely to differ from one time to the next or from one individual to the next bc of unpredictable errors, discrepancies, or natural differences that are not readily explained; a concept that we use when we talk about 2 or more measurements in relation to each other measurement error - correct answers the amount by which each measurement differs from the true value natural variability - correct answers results from changes across time in the individual or system being measured pilot study - correct answers a small group of people are asked the questions in open form (the "pilot survey"), and their responses are used to create the choices for the closed form Ordinal - correct answers placing in order when answering Interval Data - correct answers differences between values can be found, but is NO absolute ZERO. Examples: temperature F, time Qualitative - correct answers descriptive/categorical data Quantitative - correct answers Data that is in numbers sample survey - correct answers a subgroup of a large pop is questioned on a set of topics experiment - correct answers measures the effects of manipulating the environment in some way observational study - correct answers the manipulation occurs naturally rather than being imposed by the experimenter case-control study - correct answers Meta-analysis - correct answers quantitative review of a collection of studies all done on a similar topic Case study - correct answers an in-depth examination of one or a small # of individuals unit - correct answers a single individual or object to be measured census - correct answers a survey in which the entire population is measured probability sampling plans - correct answers everyone in the population must have a specified chance of making it into the sample stratified random sample - correct answers collected by first dividing the population of units into groups (strata) and then taking a simple random sample from each cluster sampling - correct answers the population units are divided into groups, called clusters, then a random sample of clusters is selected and only those clusters are measured systematic sampling - correct answers you divide the list into as many consecutive segments as you need, randomly choose a starting point in the first segment, then sample at that same point in each segment (every "kth" subject) random digit dialing - correct answers a simple random sample of all adults in the US who have telephones multistage sampling - correct answers when everyone on the block or within the fixed area is sampled (uses combo of sampling methods) Difficulties in sampling - correct answers 1) Low response rate 2) Using the wrong sampling frame 3) Not reaching the individuals selected Disasters in sampling - correct answers 1. Getting a volunteer or self-selected sample 2. Using a convenience or haphazard sample Margin of error - correct answers (1/sqrt (n) x 100) ; "n" is the size of the sample Parameter - correct answers a numerical summary of the population confounding variable - correct answers a factor other than the independent variable that might produce an effect in an experiment effect modifier - correct answers modifies the effect of the explanatory variable on the outcome experimental units - correct answers the smallest basic objects to which we can assign different treatments in a randomized experiment observational units - correct answers the objects or people measured in a study placebo - correct answers looks like the real drug but has no active ingredients Double-blind - correct answers experiment in which neither the participant nor the researcher taking the measurements knows who had which treatment Single-blind - correct answers only one of the two, the participant or the researcher taking the measurements, knows which treatment the participant was assigned Matched-pair design - correct answers experimental designs that use either two matched individuals or the same individual to receive each of two treatments; a design in which one creates a set of two participants who are highly similar on a key trait and then randomly assigns individuals in the pair to different groups Randomized block design - correct answers similar experimental units are first placed together in groups called blocks ; treatments are randomly assigned separately within each block ; done for each block to ensure that all treatments are assigned at least once in every block Repeated-measures design - correct answers the same participants are measured repeatedly Hawthorne effect - correct answers participants in an experiment respond differently than they otherwise would just because they are in the experiment ; people behave differently just because they're in an experiment case-control study - correct answers "cases" who have a particular attribute or condition are compared with "controls" who do not retrospective - correct answers participants are asked to recall past events prospective - correct answers participants are followed into the future and events are recorded ecological validity - correct answers The extent to which a study is realistic