PSY2002 SEMESTER 1 - WEEK 4

Question 1

define model

Answer 1

simplified (idealised) representation of a thing

Question 2

define statistical model

Answer 2

mathematical relationship between variables, that hold under specific assumptions (no real explanation of what is going on, why there is relationships)

Question 3

define theoretical model

Answer 3

description of relationship between different mental processes, that make assumptions about nature of these processes (tried explaining relationships between variables)

Question 4

define regression

Answer 4

same as correlation and is a single line through graph representing trends (as seen in statistical models)

Question 5

outline what cognitive box-and-arrow models are (informal theoretical model)

Answer 5

describe relationship between different mental processes, under assumption that mind operates like multi-staged info processing machine
manipulate input and observe output to have look at mind, allow testing models

Question 6

what are formal cognitive models (theoretical)

Answer 6

mathematical description of relationship between mental processes
box and arrows switched for formula to describe our cognitive process, explain them (often computer codes)

Question 7

outline simplification and abstraction (common model characteristic)

Answer 7

only describe parts of info we think are critical for what we’re trying to represent
simplification: making something simpler
abstraction: generating general rules and concepts from specific info

Question 8

what does the right level of abstraction depend on

Answer 8

question being asked, what we’re trying to convey

Question 9

who was Popper, influence in theories

Answer 9

influential in differentiating between scientific and non-scientific theories
suggest non-scientific theory only explains “after fact” and can’t provide falsifiable prediction

Question 10

name the 5 stages of models being used for prediction and explanation

Answer 10

framework, theory, model, hypothesis, data

Question 11

define framework

Answer 11

conceptual system that defines terms and provides context (eg, cognitive psychology)

Question 12

define theory

Answer 12

scientific proposition that provides relations between phenomena (eg, early selection theory)

Question 13

define model

Answer 13

schematic representation of theory, more limited in it’s scope (eg, Broadbent’s filter model)

Question 14

what should we do if framework keep producing bad theories that are always rejected

Answer 14

should change framework - falsification

Question 15

give an example of explanation without exact prediction, and then prediction without explanation

Answer 15

Ew/oP: models of sz can indicate causes but can’t predict individual cases
Pw/oE: some models can predict whether an individual will develop AD even though not that close to understanding factor explaining AD

Question 16

what are informal cognitive models

Answer 16

verbal description of relationship between different cognitive procedure, where some assumptions are often implicit and only provide directional prediction

Question 17

what are formal/computational model

Answer 17

mathematical description of relationship between different cognitive procedure, often instantiated via computer program/simulation
with explicit assumptions, providing often specific numerical prediction

Question 18

formal models allow more specific predictions. what does having numerical simulation of this model mean

Answer 18

see if model provide unreasonable prediction so is easier to reject bad models
help us select what experiments to perform (if predictions suggest exact same, no point in running experiments)
provide subtle hypothesis testing, to see how close model is to predicting an actual result

Question 19

formal models allow counter-intuitive predictions. why is this an advantage

Answer 19

model can more clearly describe which predictions follow from model
informal models are hard to notice when making counter-intuitive prediction but formal are clear

Question 20

a benefit of formal model is explicit assumption, why

Answer 20

allows reveal of unanswered questions, flaws of reasoning, contradictory/unreasonable assumptions and allows assumptions transparent allowing development and futhering of existing theories for improvement

Question 21

what are disadvantages of formal model

Answer 21

1. needs expertise
2. best compared against other computational model
3. numerical predictions can be premature
4. changing model take time and limit progress

Question 22

outline David Marr’s level of analysis

Answer 22

idea that we can understand and model a system at a number of levels (3 levels of understanding)
we can only sample tiny fraction of brain’s activity, so this provides solution

Question 23

state Marr 3 levels

Answer 23

1. computational level
2. algorithm level
3. implementation level

Question 24

what is compuational (1) David Marr levels

Answer 24

problem being solved

Question 25

what is algorithm (2) David Marr 3 levels

Answer 25

steps/rules to solve it

Question 26

what is implementation (3) David Marrs 3 levels

Answer 26

actual machinery

Question 27

why are top-down approaches not pure, where is it most common

Answer 27

use knowledge of available data so limits POV
common in cognitive science, AI

Question 28

where is bottom-up approach more common

Answer 28

cognitive neuroscience

Question 29

did Marr believe top-down or bottom-up was better

Answer 29

top-down = not overloaded by infinite amount of data we could find
but best way is to consider all 3 levels at same time

Question 30

apply bottom-up approach to David Marr levels

Answer 30

start at implementation (build model of neural networks), then ask what representations/algorithms can be generated (2nd level), then ask what kind of problems can be solved with these algorithms

Question 31

apply top-down approach to David Marr levels

Answer 31

1. problem first - what is problem we need to solve?
2. then rules- what representation/algorithms can solve it
3. then implementation- how can representations/algorithms be implemented in neural circuits

Question 32

give an issue of using top-down approach for David Marr levels

Answer 32

if identify potential algorithm at level 2, no garuntee could model neural circuits capable of implementing this

Question 33

whats an implicit model

Answer 33

assumption hidden, internal consistency untested, logical consequences and relation to data unknown

Question 34

whats an explicit model

Answer 34

assumptions shown, can be studied, sensitivity analysis to identify most salient uncertainties and important thresholds

Question 35

how does using modelling change focus from testing hypothesis to testing formal model and why is this good

Answer 35

forces scientist to document what theory assumes, allows comparison to other models and compare different parameter value effects within a model

Question 36

what is pizza problem

Answer 36

if we don’t make thinking explicit via formal modelling then have massive inconsistency in our understanding of own models

Question 37

what is path function

Answer 37

function where output is dependent on path of transformations that inputs undergo

Question 38

whats specification

Answer 38

formal description of system to be implemented based on theory, providing means of discriminating between theory-relevant, closer to core claims of theory and theory-irrelevant, auxiliary assumptions

Question 39

what is implementation

Answer 39

instantiation of models created using anything and in computer modelling usually codebase written in 1 or more programming languages

Question 40

what are open theories

Answer 40

developed explicitly, defined formally, explored computationally, more robust to failures of replication (if detected can be explained and drive theory creation not just rejecting theory)