Aantekeningen Beschrijvende en Inferentiële Statistiek
15 views 0 purchase
Course
Beschrijvende en Inferentiële Statistiek
Institution
Vrije Universiteit Amsterdam (VU)
Dit is een samenvatting van de colleges en de kennisclips van Beschrijvende en Inferentiële Statistiek bij de VU. Alle stof van module 0 tot 13 komt hier aan bod. Ik had een 7 voor dit tentame.
Termen
Werkcollege 1 (7/2/2023)
Type variabelen:
Categorisch (nominaal en ordinaal): Variabelen zoals lievelingskleur. Je kan er niet echt mee rekenen.
Nominal: when it has a noun, like someone's hair colour. You need a name for it.
Ordinal: Involves arranging numbers. it's organised, if something is on a scale of 1-5, 3 will never be an
extreme value.
Kwantitatief (discreet en continu): Getallen waar we mee kunnen rekenen.
Continuous: A continuous scale of something, like temperature. Like a gay person with a partner.
Discreet: Something that is not connected. Imagine like someone with internal homophobia, they're always
alone.
CALCULATING PERCENTAGES
Deel/geheel x 100
If change: new/old x 100
Verdeling van de data (data distribution):
● Uni-/ bimodaal
● Scheefheid
● Normaalverdeling (“bell shape”)
Grafiek, grafische weergave:
Categorisch
● Pie chart (taartdiagram); bar chart (staafdiagram)
Kwantitatief
● Histogram; stem-and-leaf plot; dot plot; box plot
Centrummaten:
Mode
● Value that occurs most frequently.
● Often used if a variable is measured on a nominal or ordinal level.
● You can have more than one mode.
Median
● Middle value of your observations when arranged from the smallest to the largest.
● When you have an even number of cases take the average of the middle numbers.
,Mean
● Sum of all the values divided by the number of observations.
Bij een left skewed graph:
1: Mean.
2: Median.
3: Mode.
Spreiding:
● Standaarddeviatie
● Variantie
● Range
● Interkwartielafstand (IQR)
Range
● Difference between the highest and lowest value.
● Subtract the lowest from the highest number to find.
● Advantages: Easy to understand, simple to compute.
● Disadvantages: Doesn't give a good impression of the variability, only takes into account the
extreme values.
, Interquartile range
Leaves out the extreme values. Divides a graph in four
equal parts. These are called quartiles. Q2 is the
median. The interquartile range is the distance
between the third and the first quartile.
Q2 = median
Q1= middle value left side of median
Q3= middle value right side of median
IQR= Q3 – Q1
Variance
Σ(𝑥−𝑥̄)
s2= 𝑛−1
S2: Variance
(x - x̄): From every observation (x) you have to subtract the mean variable (x̄), square all these values and add
them up. This result is the sum of squares.
N - 1: Divide the sum of squares with the sample size (n) - 1.
Disadvantage to using variance: the metric of the variance is the metric of the variable under analyses
SQUARED.
Standaarddeviatie
De standaarddeviatie geeft aan hoeveel de data Gemiddeld afwijkt van het gemiddelde.
Voor uitrekenen:
● Je kijkt eerst naar hoeveel elke observatie van het gemiddelde afwijkt.
X - x̄
●
● Standaarddeviatie zegt dus iets over de spreiding. Dit zegt iets over de zekerheid.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller FlyingRaven. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $6.32. You're not tied to anything after your purchase.
