Philosophy of science Flashcards
Experts
In a specified domain have a greater quantity of accurate information than most people do
Laypeople (novices):
Little information in the specified domain
The novice-experts problem
How should novices choose one putative expert as more credible or trustworthy than another
Possible strategies to adress the novice experts problem (arguments presented)
Advantage: Information from putative experts is widespread and easily available
Problem: How can a novice make an accurate assessment of the putative experts arguments and technical language
Possible strategies to adress the novice experts problem (agreement with other experts
Advantage: For any domain, there is typically more than one expert, and the great majority of experts agree on a certain view
Problem: There are many possible reasons why people in a field might agree, and such agreement doesn’t always signal that they are all correct
Possible strategies to adress the novice experts problem (Appraisal by meta experts)
Advantage: Degree, prizes, work experience etc. Reflect publicly available certifications by other experts of ones expertise
Problem: Novices are not always in a position to assess the significance of ones credentials
Possible strategies to adress the novice experts problem (conflicts of interest)
Advantage: sometimes, conflicts of interest are clear
Problem: In many contexts, novices cannot easily detect more subtle conflicts of interest
Possible strategies to address the novice experts problem (past track-record)
Advantage: It seems easy to check how many times and in what situations a putative epert got it right
Problem: For complex phenomena, it may be beyond the novices capacity to check whether a putative expert got It right
Illusion of understanding
People feel they understand complex phenomena with far greater precision, coherence and depth than they really do; they are subject to an illusion of explanatory depth
Non-scientific practices
Do not aim at generating knowledge in the same way science does; their proponents try to create the false impression that they generate genuine trustworth knowledge
Pseudo-scientific practices
Are not scientific, but their proponents try to create the false impression they generate genuine trustworthy knowledge
Science is a practice
Socially and institutionally organized
Aimed at producing knowledge about natural phenomena
Reproducible studies
Can be performed again
Produces the same or sufficiently similar ersults as the original study
Why replicate a study
Limits the role of luck and error
E.g. False positives (type 1 error)
False negatives (type 2 error)
INcreases confidence a hypothesis is true (or false)
e.g. more evidence from different sources/labs
Helps science to self-correct
Why do many results fail to replicate
Fraud
Questionable research practices (hacking - checking statistical significance of results before deciding whether to collect more data
Incentive structure and organization of science institutions
Examples of social-institutional conditions that influence self-correcting
Open datasets
Replace null hypothesis significane testing
Reward replication work
Publish negative results
Diversity science
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Three common features of scientific practice
1) publicly shared (oft mathematical) representations and techniques (hypothesis)
2)openness to criticism (Grounded in hypothesis)
3) empirical evidence
Rationale for experimental control
Any measured change in the dependent variable is due only to the intervention
By dividng participants randomly
You (supposedly) distribute participants with particular characteristics “equally” among the two groups. This would minimize the differences between the two groups with all known and unknown extraneous variables
Does randomization really solve the problem of variable control?
Not really: Random group assignment does not guarantee that researchers selection of experimental groups does not distort experimental results
BUT
Random group assignment does not guarantee that extraneous variables do in fact vary equally across the two groups in any single experiment
It is only over an indefinite series of repetitions of the random division that the variables Z will be equally distributed between the two groups
Repeat random division a lot and a lot of times and the frequency of education in one group will be about the same as the frequency of education in the other group
But
Researchers do not make random division of experimental participants indefinitely often, they do it once
Whats data science
Use of computational, algorithmic, statistical and mathematical techniques to analyse and gain knowledge from the big data
Any tool for data analysis does:
Makes assumptions (e.g. about the statistical structure of the data, about how to weigh different data etc.)
Based on algorithms
“trained” or “labelled” sample data to extract patterns or to make predictions
The bay model
A model oft he san franciso bay: a downsized reconstruction of the bay in san Francisco
1000 times smaller than the actual bay
Mimics the tides and currents of the actual bay
Scientific model: used to learn not just about the model but about the actual bay
John reber wanted to fill parts of the bay by building a dam
The model showed this was not a good idea
By manipulating and studying the model we can learn about the actual bay
Models
Models represent a target system: models are about something else, namely their target
How do models represent their target? By being relevantly similar, not by being identical
The bay model replicated tides and currents but not the number of sailboats or the houses on the coast
Models are incomplete and simpler versions of their target, theyre idealiizations
The bay model has much faster tidal cycles
Models are thus abstractions of their target
Representations
These involve triadic relation between an agent or human representation and a represented world
Models that exemplify
For a model to exemplify a (group of) target systems it must be a group member
Fruit fly (Drosophila melanogaster) s a model organism in genetics and developmental biology
Mice are model organisms in biology and medicine to model human diseases
Fruit flies and mice are relevantly similar to their target system, in this case humans, but there are of course many differences
Why model at all
When its impossible to perform experiments on the target (solar system)
When its impractical to perform experiments on the actual target (The Bay model)
When its immoral to perform experiments on the actual target (Using mice as a model organism to test vaccines for covid)
Models of data
A model of data, or data model, is a regimented representation of some data set, often with the aim of highlighting whether or not the data count as evidence for a given hypothesis
Data are any public records produced by observation, measurement or experiment
Raw data
Video recordings of capupchin monkey behavior, observations of teh position of planets in the night sky, readings of a thermometer, participants answers on a questionnaire in a psychology experiment
Models of data (steps involved)
1) Eliminating errors
2) Displaying measurements in a meaningful way
3) Extrapolating from those measurements to the expected data for measurements that weren’t actually taken
Scale models
Concrete physical objects that serves a down-sized or enlarged representation of their target system
Building a model
1) specification of the target system(s)
2) Construction of the model
3) analysis of the model
The solar system
How is the model build in the documentary similar to its target system and how is it different
Similar: in terms of the size of the planets and the distance between them
Different: the composition of the planets, no atmosphere on earth, no satellites, no comets or debris
Mechanistic models
Mechanistic models are representations of mechanisms
Mechanisms are organized systems consisting of component parts and component operations that are organized spatially and temporally, so as to causally produce a phenomenon
Mechanistic models represent the causal activities of organized component parts that produce some such phenomenon
This illuminates how the target phenomenon works and how it depends on the orchestrated functioning of the mechanism that produces it
Computer models
Computer models or simulations are programs run on a computer using algorithms to explore aspects or changes to a target system
Thomas schellings checkerboard model of segregation (3 assumptions)
Assumption 1:
Two sorts of agents
Agents live in a two-dimensional grid
Agents initially randomly distributed on the grid#
Assumption 2:
Agents have preferences for their neighbourhood
Agent satisfied only if surrounded by at least t% (e.g. 30%) of agents like its self
Assupmtion 3:
Agents interact accordingly to a behavioural rule
When an agent is not satisfied the agent moves to any vacant location on the grid
Idealized models
Deliberately simplified or distorted representations
Omitting, abstracting from certain known features of a target system/phenomenon
Why?
Make the model easy to construct, manipulate, analyse and run on a computer.
Individual choices
Can lead (under specific conditions) to significant unintended consequences for larger groups
Model
Idealized representation of something compicated with the goal of making it more simple/tracable or understandable
Building a model
Figuring out what should be included in the model and how given certain aims is an opportunity to learn about the model
Manipulating a model
Figuring out how the model changes if you intervene on it in some way is an opportunity to learn about the odel
Representation (model)
Meant to stand in for their target systems
Different features of model more or less similar to certain features of target system