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<<SAMPLE AND SURVEYS OBESERVATIONAL STUDIES AND EXPERIMENTS>…
<<SAMPLE AND SURVEYS OBESERVATIONAL STUDIES AND EXPERIMENTS>> 
NON- SAMPLING ERRORS
WORDING BIAS- Using a tone to give someone 2 different options or two different options. EXAMPLE: A survey participant is in a public setting where he/she does not think that his/her answer would be socially acceptable, so he/she answers untruthfully.
RESPONSE BIAS: The tendency of a person to answer questions on a survey truthfully. EXAMPLE: A survey participant does not have much time to respond to the prompts, so they do not answer it as honestly or truthfully as thy would have otherwise.
NON- RESPONSE: Participants of the survey who did not respond to the survey or a certain part of the survey.
SAMPLING ERRORS
CONVENIENCE SAMPLE - a sample made up of people who are easy to reach. EXAMPLE: One is looking for a quick answer to a question. He asks the closest 10 people to him.
VOLUNTARY RESPONSE SAMPLING- made up of volunteers, this samples are always biased EXAMPLE: One is doing a survey at a super market and asks random shoppers what they think about the current economic state of the US.
UNDER-COVERAGE- occurs when members of a population are inaccurately represented EXAMPLE: A person is doing a survey on the satisfaction of Patriots fans with their seats at a game. Unfortunately, they only survey the people who have seats in the end zones.
BIAS- this the tendency of a measurement, or what the measurement is most likely to say.
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GOOD SAMPLING TECHNIQUES
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CLUSTER SAMPLIG - when samples are divided into clusters or small groups then, then a simple random sample of clusters is taken
SAMPLE SURVEY
How many people buy school vs how many people bring their own school lunch this survey by selecting a random group of students The source of our data would be the school in which the students reside
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OBSERVATIONAL STUDIES- the researcher has no control over the variables. EXAMPLE= for boys that are late on development does giving them testosterone supplest stimulate their growth.
EXPERIMENTS- the researcher is able to apply treatment to the groups and is able to record the effects. the experiment will have a control and a treatment. EXAMPLE- selecting kids that are late in their developments and giving some testosterone and not giving the other is does it helps the researcher figure out their hypothesis.
LURKING VARIABLE= a variable that affects both the dependent and independent variable witch at the same time influences the responding variable.
CONFOUNDING= is the result of two variables being associated in a way that their influence on the response variable cant be observed from each other.
VOCABULARY
EXPERIMENTAL UNITS- the physical entity that receives treatment. EXAMPLE: Tomato plants, trying to figure out if different environments effect growth drastically.
FACTORS- an explanatory variable, experimental unit, subject, etc. manipulated by the experimenter. EXAMPLE: amount of light, water, plant food given.
TREATMENTS- how an explanatory variable is manipulated EXAMPLE: Possibly purposely putting a plant in a more shady area.
RESPONSE VARIABLES- a technical for assigning subjects to different groups. EXAMPLE: The different amount in yield of tomato fruits from a single plant.
3 PRINCIPLES FOR DESIGN-
CONTROL= use a comparative design and ensure that the only systematic difference between the groups is the treatment groups.
RANDOM ASSIGNMENT =the use of impersonal chance or randomness to assign treatments. this helps make the groups equal it also reduces the chance of lurking variables that are not controlled on the treatment group.
REPLICATION= the use of enough experimental units in each group so that any differences in the effects of the treatment can be distinguish from chance differences between two groups
BLINDING- this is keeping he test subjects in the dark on whether they receive a placebo. If researchers did not do this, there would be not point to using a placebo.
PLACEBO EFFECT- How subjects respond to a fake treatment. For example, if researchers were testing out a new drug and they gave one group of people the actual drug and another the placebo (which could be just a sugar capsule). Studying how those who receive the placebo act is studying the effect of the placebo.