Lecture summary for Vrije Universiteit’s Statistical Methods course given in second year of Artificial Intelligence bachelors. This document summarizes all the information given in lectures and because of that is a great way to study for your exam.
Statistics : science of data ,
study of collecting ,
organising analysing
, ,
interpreting and
presenting data
( population)
gain
and/or objects
Used to information about
group a
of
predictions
to make decisions and
has to be
choose subset
e
good sample sample population
of pop .
collect
data 7
^
✓ Collect data
analysis
✓
sample and draw
data conclusions
census
statistical study
:
I .
prepare
context
.
-
source :
now was the data collected ?
sampling method : how were the participants chosen
-
2 .
Analyse
Graph data
-
Explore data
'
Apply statistical methods further investigate data
-
-
3 .
conclude
statistical and critical
thinking
.
common flaws
I Bad method
.
sampling
different sample →
different data . :
different conclusions
sample should be representative and unbiased
representative :
same characteristics as population
unbiased : no systematic difference with population
2 O data
starting misleading presentation
→
.
Not y-axis from of
3 correlation causation
. does not
imply
, collecting sample Data
Different sampling methods
voluntary response sample :
subjects decide themselves to be included
-
in sample ( biased)
Random sample : each member of population has equal probability
-
of
being selected can biased)
simple random sample each sample of size has equal
-
: n
( unbiased
probability of being chosen .
very representative and ,
but hard
to do with a large population)
systematic sampling after starting point select
every th member
-
:
, K -
'
stratified sampling : divide population into
subgroups such that
subjects within groups have same characteristics ,
then draw a
sump ie random sample from each
group
cluster divide population into clusters randomly select
'
sampling :
,
then
some of these clusters ( can lead to biased data)
convenience
sampling easily available results C biased ) C pilots)
-
: ok for
important concepts
variable :
varying quantity
in cause and effect studies :
(dependent) variable
Response representing effect to
study
-
:
the
( independent) variable effect
Explanatory
:
possibly causing that
'
variables
confounding mixing influence of several explanatory
-
: on
response
Different types of study
Observational
study : characteristics of subjects are observed ; subjects
are not modified
Retrospective ( case control) data from the past
-
-
:
sectional data point in time
-
cross -
:
from one
prospective (
longitudinal) data are to be collected
-
:
Experiment : some subject treatment
sometimes control and treatment single blind ( participant doesn't
-
groups
are there influences other variables ?
of
-
is there dependence between variables ?
-
Summarise →
describe find structure in data distribution :
Graphical :
tables graphs other
figures
-
. .
Descriptive
-
Qualitative describe location and dispersion Ivar lotion
-
shape
-
: .
-
Quantitative : numerical summaries of location lvariation
Graphical summaries :
'
Frequency distribution :
count occeerances
-
cumulative frequencies and relative cumulative) frequencies
-
Bar chart cumulative bar chart and Pareto bar chart
,
circle
diagram
-
Histogram ( can only be used for quantitative data)
-
series plot visualize
Time time varying quantity
-
: -
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper marinamssantos. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €10,99. Je zit daarna nergens aan vast.
