Foundation of CR Flashcards
[Flaws in Argument]
What three things to be wary of that falls under the “Language Weakness” category?
- Extreme Language
- False synonym or false equivalents
- Vague language
Consumers used their cell phones more this month than last month, but they talked for fewer minutes. So they must have sent more text messages this month than last month.
What kind of “Language Weakness” does the argument above display?
False synonym
“Use their cell phones more” is not necessarily equivalent to “sent more text messages”
There are other things to do on a cell phone: playing games, surfing the web, etc.
People who jog more than 10 miles per week have a lower incidence of heart disease than people who exercise the same amount of stationary bicycles. Therefore, jogging is the best method of exercise for reducing heart disease.
What kind of “Language Weakness” does the argument above display?
Extreme Language - “jogging is the best method”…
Vague Language - “exercise the same amount”… what’s “amount” measured in?
What three types of selection bias are there? What do they each mean?
Unrepresentative Bias - The selection pool does not represent the correct target
Survivor Bias - Only concentrating on who/what survived a process or time period while ignoring the non-survivors. QUESTION/ID THE NON-SURVIVORS
Ever-Changing Pool - The selection pool changed compared to before. You can’t directly compare these two.
Some customers who filled out a long survey for free said that they loved our company. So our customers love our company.
What sort of selection bias does the argument above display?
Unrepresentative bias.
“Some customers” probably only include those that like the company already.
A survey of living people over 100 showed lower rates of cig smoking that were shown in every other age group age 15 and up. Therefore, the rate of smoking is increasing.
What sort of selection bias does the argument above display?
Survivor bias.
It is likely that those who lived to be 100 did so in part by not smoking, and that plenty of people born 100 or more years ago did smoke and did not live to be 100.
Most ancient Greek coins made of gold and silver have been found buried in the ground. So the ancient Greeks must have buried most of their gold and silver coins.
What sort of selection bias does the argument above display?
Survivor bias.
Unrepresentative bias.
What about the ancient Greek coins that weren’t buried? They were probably dispersed, melted down, or otherwise destroyed. The sample of surviving coins is not representative.
A petition is circulating in Capital City opposing the building of a new sports center at State University, on land now occupied by abandoned strip malls. Five years ago, many city residents opposed the building of the new State University dormitory complex, yet in a poll this year, 80% of respondents said that building the dormitory complex had been a good idea. If the people who currently oppose the new Sports Center are patient, they will change their mind
What sort of selection bias does the argument above display?
Ever-Changing Pool
Are the poll respondent the same population as the voters? Maybe the poll consisted of mostly students that would skew the results.
Or maybe the residents 5 years ago moved away from the place and the new poll consists of new residents.
Students who joined social clubs at Hambone University last year and were elected officers of their clubs had lower grades on average than all students at Hambone over the last decade. Therefore, participation in social clubs at Hambone negatively impacts students’ grades.
What sort of selection bias can you think of for the argument above?
Self-selection bias - these kids wanted to prioritize socializing by joining social clubs
Survivor bias - these studnets were elected officers, meaning that they made it even further into socializing.
Ever-changing pool - students from last year are being compared with students over the last decade.
Participants who received Cetadone and counseling were 40% more likely to recover than were patients assigned to a control group and who received only counseling. Conventional therapies have only a 20% recovery rate. Therefore, the best way to reduce deaths from tarocaine overdoes throughout all of New Portsmouth would be to fund Cetadone therapy for all tarocaine addicts.
How would you process the percentage in the argument above?
TRAP: assume that 40% is higher than 20% and automatically agree with the argument.
40% is a percent increase of an UNKNOWN FIGURE.
20% is an actual recovery rate. (not here that conventional therapy IS NOT THE SAME as control group)
control group recovery can easily be anywhere between 0% to 100%.
Amateur boxers wear headgear to protect against brain injuries from boxing. Yet, last ear, three amateur boxers suffered serious brain injuries in the ring while wearing the headgear. Therefore, the headgear does not protect against brain injuries.
What’s the big leap in logic here?
headgear is not 100% effective -> it does not protect
maybe it wasn’t worn correctly?
There are lots of things - airbags, sunscreen, bulletproof vests - that do not provide 100% protection.
What’s the significance of a “causal relationship” in critical reasoning?
Question that relationship.
It can be the other way around:
marriage –> happiness; happiness –> marriage
Or something else can cause both of them:
$$ Catfood –> less grooming; rich ppl –> $$ catfood & less grooming
According to a recent study, cats that eat Premium Cat Food have healthier coats and shed less hair than those that do not. The higher cost of Premium Cat Food will be offset by a reduction in the need for cat grooming and house-cleaning services.
What’s the causal relationship here and what should you question about it?
Causal Relationship: Cat food –> healthier coats + reduced shedding.
Is that necessarily true tho?
Maybe people who can afford premium cat food can also provide their cats with grooming, top-notch health care.
In a survey of working freight trains, a recent study found that engines built before 1960 had better tolerances and higher-grade steel than engines built since 1960. Therefore, freight train engines were constructed according to higher quality standards before 1960 than afterwards.
What’s the argument flaw here?
Survivor Bias
The BEST of the engines before 1960 is being compare to ALL of the engines since 1960. It is possible that the former now only consists of engines that have no flaws, making the comparison unfair towards the latter.
Company G determined that there were two available methods to cut production costs for its main product line: change suppliers for certain raw materials or automate certain steps in the assemble of the product. Automation will save more money than changing suppliers, so Company G will maximize its savings by automating certain steps of the assembly.
What’s the argument flaw here?
unjustified language + causation
“Maximize” indicates that ONLY automation will work. What if BOTH automation AND changing suppliers is even more effective?
