Power en steekproefgroottes berekenen

Je wilt het gemiddelde investeringsbedrag per financieringsronde vergelijken tussen gamebedrijven en advertentiebedrijven. Je begint met het berekenen van de power van een t-toets voor twee steekproeven.

Drie dingen zijn voor je ingeladen:

ads_acquired_avg_funding - (pandas Series) Het gemiddelde investeringsbedrag van elk overgenomen advertentiebedrijf
games_acquired_avg_funding - (pandas Series) Hetzelfde, maar dan voor gamebedrijven
ads_games_cohensd - (Getal) Cohen's d (gestandaardiseerde effectgrootte) voor advertentie- versus gamebedrijven

De functie die nodig is om de power te berekenen is geïmporteerd uit statsmodels.stats.power.

Deze oefening maakt deel uit van de cursus

Basis van inferentie in Python

Cursus bekijken

Praktische interactieve oefening

Probeer deze oefening eens door deze voorbeeldcode in te vullen.

# Compute the ratio of games to advertising companies
games_ads_ratio = ____ / ____

# Compute the power of the test
____().____(effect_size=____, 
            nobs1=____,
            alpha=____,
            ratio=____)

Code bewerken en uitvoeren

Deze oefening maakt deel uit van de cursus

Basis van inferentie in Python

SkillTag.level.advancedSkillTag.label

4.9+

Begin de cursus gratis

In this chapter, we'll explore the relationship between samples and statistically justifiable conclusions. Choosing a sample is the basis of making sound statistical decisions, and we’ll explore how the choice of a sample affects the outcome of your inference.

Exercise 1: Statistical inference and random sampling Exercise 2: Sampling and point estimates Exercise 3: Repeated sampling, point estimates and inference Exercise 4: Sampling and bias Exercise 5: Visualizing samples Exercise 6: Inference and bias Exercise 7: Confidence intervals and sampling Exercise 8: Normal sampling distributions Exercise 9: Calculating confidence intervals Exercise 10: Drawing conclusions from samples

Learn all about applying normality tests, correlation tests, and parametric and non-parametric tests for sound inference. Hypothesis tests are tools, and choosing the right tool for the job is critical for statistical decision-making. While you may be familiar with some of these tests in introductory courses, you'll go deeper to enhance your inferential toolkit in this chapter.

Exercise 1: Normality tests Exercise 2: Testing for normality Exercise 3: Distribution of errors Exercise 4: Fitting a normal distribution Exercise 5: Correlation tests Exercise 6: Testing for correlation Exercise 7: Autocorrelation Exercise 8: Explained variance Exercise 9: Parametric tests Exercise 10: Equal variance Exercise 11: Normality of groups Exercise 12: ANOVA Exercise 13: Non-parametric tests Exercise 14: Comparing rankings Exercise 15: Comparing medians

In this chapter, you'll measure and interpret effect size in various situations, encounter the multiple comparisons problem, and explore the power of a test in depth. While p-values tell you if a significant effect is present, they don't tell you how strong that effect is. Effect size measures how strong an effect a treatment has. Master the factors underpinning effect size in this chapter.

Exercise 1: Effectgrootte Exercise 2: Effectgrootte voor gemiddelden Exercise 3: Effectgrootte voor correlaties Exercise 4: Effectgrootte voor categorische variabelen Exercise 5: Meerdere vergelijkingen en correcties Exercise 6: Probleem van multiple comparisons Exercise 7: Bonferonni-Holm-correctie Exercise 8: Power van een toets Exercise 9: Wat is power eigenlijk?Exercise 10: Power voor experimenteel ontwerp Exercise 11: Power en steekproefgroottes berekenen

Huidige oefening

You’ll expand your inferential statistics toolkit further with a look at bootstrapping, permutation tests, and methods of combining evidence from p-values. Bootstrapping will provide you with a first look at statistical simulation. In the lesson meta-analysis, you’ll learn all about combining results from multiple studies. You’ll end with a look at permutation tests, a powerful and flexible non-parametric statistical tool.

Exercise 1: Bootstrapping Exercise 2: Bootstrap confidence intervals Exercise 3: Bootstrapping vs. normality Exercise 4: Combining evidence from p-values Exercise 5: Fisher's method in SciPy Exercise 6: Inference using Fisher's method Exercise 7: Summarizing Fisher's method Exercise 8: Permutation tests Exercise 9: Permutation tests for correlations Exercise 10: Permutation tests and bootstrapping Exercise 11: Analyzing skewed data with a permutation test Exercise 12: Course wrap-up video