Critical Thinking

Front 1

Parts of an analogical argument

Back 1

Analogue

Primary Subject

Similarities

Conclussory Feature

Front 2

TP test

Back 2

Premises accurately describes the world and commits no fallacy. Premises are empirical, direct indirect,Testimonial (indirect), CLEAR (Expert). Sticks to Audience

Front 3

Analogical Argument Form

Standardization

Back 3

Premise one: X1's have features F1, F2, F3, etc and feature Fc. Premise 2: X2's also have features F1, F2, F3, etc. Therefore, conclusion: X2's probably have feature Fc. X1 and X2 refer to entities or things in the world.

Ex.

(1) People in the first two years of elementary school are students who generally attend classes between 9am and 3pm, and their instructors tell them when to go to lunch and to form a line when they do so.(2) People in the first two years of college are students who generally attend classes between 9am and 3pm.Therefore,(3) Instructors should tell college students in their first two years when to go to lunch and to form a line when they do.

Front 4

Evaluation ( Analogical)

Back 4

EvaluationParts Analogue: first and second graders;Primary subject: college freshmen and sophomores. Similarities: students in their first two years, attending classes 9-3. Conclusory feature: requiring permission and being in a line to go to lunch

Front 5

Pf Test (Analogical)

If _____ are true the the _____is true

Back 5

PF test:The argument is an inductive analogical argument, because the argument is based on a comparison and the premises only make the conclusion likely to be true. The premises are neither individually nor jointly relevant to the conclusion because the two similarities are not relevant to the conclusory feature (maybe a tiny bit of relevance since they are in school during typical lunch time). Indeed, class times in College have no bearing on the two conclusory features, since college students are autonomous. There are also significant relevant dissimilarities between the analogue and the primary subject such as (a) a large gap between the age, cognitive development, socialization level of elementary children and college students, (b) the fact that college students do not take all of the same classes at the same times as each other so would not even want to eat at same time, (c) the fact that college students may eat anywhere or nowhere so would never all go at once in or out of a line, just to name three of the many dissimilarities that could be mentioned. The argument does not do well at all on the proper form test, it is a very weak form.

Front 6

TP Test (Analogical)

Back 6

TP testThe audience of this argument is PHIL 1010 students, since they are freshmen. The argument is appropriate to that audience, because 1010 students learn about the functioning and the organization of college. This is an imaginary argument made up for the test, but there are no imaginary cases appealed to in the premises. Both premises are empirical and direct, since one can observe what they are about and there is no source reporting this passage. Based on my background knowledge, the premises should be accepted as uncontroversially true. Therefore, the argument passes the TP test.

Front 7

Fallacies and Global Comment

Back 7

Fallacies and Global. Although this argument passes the true premise test, it fails the proper form test because of relevant dissimilarities between both the similarities and the conclusory feature, and the analogue and the primary subject. Because the dissimilarities are significant, this argument is terrible and thus non-cogent.

Front 8

Statistical Argument

GENERAL Form

Back 8

The general form of a statistical argument only has one premise, and then the conclusion. Premise (1) is just that P% of the S observed things in G have F.Therefore, P% of all the things in G have F

The observed things in G are the sample.The S is the number of things in the sample. The features that the observed things have, the F, is the relevant property. All the things in G are the target. And the P is the percentage of the observed things that have F (the relevant property).

Front 9

Standardization (Statistical)

Back 9

1) 100% of the one observed (bacteriophage) virus had the feature of remaining viable for up to 24 hours on a plastic toy.Therefore,(2) 100% of all enveloped viruses such as influenza will have the feature of remaining viable for up to 24 hours on plastic toys.

Front 10

Evaluation (Statistical)

Back 10

EvaluationPartsG sample= sample of a bacteriophage virusP = 100% (only one sample)S = one F = viability lasting 24 hoursG target population= all enveloped viruses

EvaluationPartsG sample= sample of a bacteriophage virusP = 100% (only one sample)S = one F = viability lasting 24 hoursG target population= all enveloped viruses

Front 11

TP Test (Statistical)

Back 11

TP testThe audience of this argument could be scientists or doctors since they are interested in hygiene and children’s health. Given this reason, the argument is appropriate to that audience. The premise is an empirical statement: this is something one can observe with a microscope. The premise is also an experts’ statement made by two researchers at GSU. This scientific source seems to pass the CLEAR test: they have the credentials and the area of expertise. There is no other way I can assess its reliability. So, given the reliability of the experts and my background knowledge (I am not a medical or biology student, but it seems plausible to me), the premise should be accepted as uncontroversial true. This argument passes the TP test.

Front 12

PF Test (Statistical)

Back 12

PF testThe argument is an inductive statistical argument as it is a generalization that is likely to be true. The premise is somewhat relevant to the conclusion. It is probably not known to the 1010 audience whether or not bacteriophages are sufficiently similar to other viruses to be able to determine whether the premise is relevant. The sample is clearly small and also lacks variety: the sample is only one particular type of virus. To test only one type of virus (on one type of toy) seems to commit both the hasty generalization fallacy and the biased sample fallacy, since they are many types of viruses. However, if we assume that the scientists consider the one type of bacteriophage to be sufficiently similar to other viruses, then we would say it does not commit the biased sample fallacy. However, the sample does still appear to be too small. Moreover, there are other dissimilarities that may or may not be important. The test was run in a controlled humidity environment whereas toys handled by children may not be in such a controlled environment. It is difficult to determine how well the argument does on the PF test. If we take the experts’ testimony fully, we would say it does pass. However, I do not have enough information about the scientists to fully rely on their judgement. That is the reason why I claim that this argument is hasty generalization and has a biased sample for the reasons given above. This argument fails the proper form test.

Hint 12

You apply the True Premises test as outlined in Chapter Two with the revisions noted in Chapter Three. As far as the Proper Form test is concerned, a statistical argument passes the Proper Form test when it can be put into the form of a statistical argument, and the sample is sufficiently representative.

Front 13

Fallacies and Global Comment (Statistical)

Back 13

Fallacy and GlobalThe argument may commit a hasty generalization since it only tested one sample. It may also commit the biased sample fallacy, but not if we take the expert testimony at face value. If the latter then we would say it is a cogent argument passing both tests and therefore a good argument. If we don’t take the expert testimony as final, we would say it passes the TP test but does not do quite as well on PF so is not cogent and not a good argument. I personally think that this is not a good argument, because we should not blindly accept experts’ statements when we do not have sufficient information as to their reliability. So this argument has a weak form and is non-cogent.

Front 14

So what makes a sample representative?

Back 14

A sample is perfectly representative when the proportions of every subgroup in the target are exactly matched by the proportions of the subgroups in the sample. On the other hand, a sample is biased when the proportions of every subgroup in the target do not match the proportions of the subgroups in the sample.

Front 15

How do we get representative samples?

Back 15

How do we get representative samples? There are some guidelines that help us. The first guideline is size. The larger the sample, the more likely it is that the sample is representative. A sample must be a sufficiently large percentage of the target if it is to be representative. The second guideline is variety.The more varied the sample, the more likely it is that the sample is representative. The sample must have the same kind of variety as the target. Let's look at an example. A sample of crows for making an argument about normal crows in the wild is taken, and it consists of 100 tame, albino crows.Think about the size. The sample size is too small. There are millions of wild crows. What about the variety? The sample does not have adequate variety. Albino crows are rare in the wild, and tame crows and wild crows may be very different in many respects. So, this sample is not representative.

Front 16

simple random samples

Back 16

A simple random sample is one in which all the things in the target have an equal chance of being in the sample

Front 17

stratified random samples

Back 17

In a stratified random sample, the target is first divided into subgroups and then a simple random sample is taken of each subgroup. This can be the best way to produce a representative sample.

Front 18

Systematic Samples

Back 18

In a systematic sample, every Nth thing in the target is put into the sample.This does not usually reflect the variation in the target, and does not work for large unknown targets.

Front 19

A voluntary response sample

Back 19

A voluntary response sample is composed of people who voluntarily choose to respond to the call for data. This is the sampling method most commonly used in surveys distributed by mail. It's rarely representative.

One problem with voluntary response samples is the problem of nonresponse. Some entities in the sample don't supply data.

Front 20

A haphazard sample

Back 20

A haphazard sample is a sample chosen with no method at all.

This should not be confused with a random sample.To get a random sample, you have to be sure to try to get a random sample. That is not the same thing as choosing with no method at all.

Haphazard samples are unlikely to generate representative samples.

Front 21

Purposive Sample

Back 21

In a purposive sample, the researcher selects the target based on fixed proportions.The target is separated into subgroups called strata, and a fixed proportion of the sample is taken from each strata.

It's easily confused with a stratified random sample, but the difference is that in a purposive sample, there is no random selection.

Front 22

A convenience sample

Back 22

A convenience sample consists of those entities which are easiest for the researcher to reach.They're usually geographically limited, and they may not be representative of the target.

Front 23

A census Not A Sample

Back 23

A census occurs when a researcher observes each and every thing in the target

A census occurs when a researcher observes each and every thing in the target

Front 24

Examples of Samples

Back 24

What type of sample is the U.S. Census? Well, it's called a census, but it's a voluntary response sample because people can refuse to take the census surveys. What about a phone survey?That's a voluntary response sample. What about 100 rats selected at random out of the rats in a lab? That's a simple random sample. What about a selection of rats first divided into groups by sex, and then randomly selected from each group? That's a stratified random sample. What about a selection of 25% freshmen, sophomores, juniors and seniors out of a school?That's a purposive sample. What about a selection of the cows seen on a drive home to talk about cows all over the world? That's a haphazard sample. What about a selection of 10 zebra fish from a tank of 50 caught by waving a net randomly through the tank while saying," Here, fishy, fishy"?That's also a haphazard sample.