Weighted_Average_Rating_Calculation

Business Problem

In this section, we will rank the datasets by their weighted average ratings. This method takes into account both the ratings and their relative importance, providing a more accurate comparison. As a result, the rankings better reflect the true quality of each dataset.

Import Necessary Libraries

import numpy as np
import pandas as pd
from sklearn.preprocessing import MinMaxScaler

pd.set_option("display.max_columns", None)
pd.set_option("display.max_rows", None)
pd.set_option("display.width", 500)
pd.set_option("display.float_format", lambda x: "%.2f" % x)

Import Dataset

df = pd.read_csv("course_reviews.csv")
df.head()

General Information About Dataset

Since we want to check the data to get a general idea about it, we create and use a function called check_df(dataframe, head=5, tail=5) that prints the referenced functions:

def check_df(dataframe, head=5):
    print(20*"#", "Head", 20*"#")
    print(dataframe.head(head))
    print(20*"#", "Tail", 20*"#")
    print(dataframe.tail(head))
    print(20*"#", "Shape", 20*"#")
    print(dataframe.shape)
    print(20*"#", "Type", 20*"#")
    print(dataframe.dtypes)
    print(20*"#", "NA", 20*"#")
    print(dataframe.isnull().sum())
    print(20*"#", "Quartiles", 20*"#")
    print(dataframe.describe([0, 0.01, 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 0.95, 0.99, 1]).T)

Data Pre-Processing

In the data preprocessing stage, we use the pandas library to convert the "Time Stamp" feature into a format that pandas can recognize as dates. We then find the maximum date and define current_date as a few days after this maximum. Finally, we calculate the difference in days between current_date and each timestamp, and add this difference as a new feature called "days" in the dataframe.

df["Timestamp"] = pd.to_datetime(df["Timestamp"])
current_date = pd.to_datetime("2021-02-10 00:00:00")
df["days"] = (current_date - df["Timestamp"]).dt.days

Time Based Average

Time-Based Average calculation involves computing average values of data by considering specific time intervals to understand trends. This code snippet calculates the average ratings for different time ranges and applies weights to these averages based on the time period. It gives higher weights to more recent ratings, reflecting the impact of time on the average score and resulting in a balanced rating that accounts for temporal effects.

df.loc[df["days"]<=30, "Rating"].mean() * 28/100 + \
df.loc[(df["days"]>30) & (df["days"]<=90), "Rating"].mean() * 26/100 + \
df.loc[(df["days"]>90) & (df["days"]<=180), "Rating"].mean() * 24/100 + \
df.loc[df["days"]>180, "Rating"].mean() * 22/100

User Based Average

User-Based Average Calculation calculates a weighted average rating based on different rating ranges. The code snippet computes the average rating for various rating ranges and assigns different weights to these averages. Ratings within higher ranges are given more weight, reflecting their greater significance in the overall average rating.

user_based_weighted_average = sum(similarity user * user preference) / sum(similarity)

df.loc[df["Progress"]<=10, "Rating"].mean() * 22/100 +\
df.loc[(df["Progress"]>10) & (df["Progress"]<=45), "Rating"].mean() *24/100 +\
df.loc[(df["Progress"]>45) & (df["Progress"]<=75), "Rating"].mean() * 26/100 +\
df.loc[df["Progress"]>75, "Rating"].mean() *28/100

Course Weighted Rating

In the "course weighted rating" section, we combine user-based and time-based averages to create a single rating. This approach accounts for both user progress and the timing of ratings, resulting in a more balanced and accurate evalua

time_based_weighted_average(dataframe) * 40/100 + user_based_weighted_average(dataframe) * 60/100

Pipeline

In the pipeline section, all the code for time-based and user-based average calculations is combined into one structure. This allows running just this part to produce the final result.

dataframe["Timestamp"] = pd.to_datetime(dataframe["Timestamp"])
current_date = pd.to_datetime("2021-02-10 00:00:00")
dataframe[day_column] = (current_date - dataframe["Timestamp"]).dt.days

# time based weighted average
time_based_avg = dataframe.loc[dataframe[day_column]<=30, rating_column].mean() * tw1/100 + \
dataframe.loc[(dataframe[day_column]>30) & (dataframe[day_column]<=90), rating_column].mean() * tw2/100 + \
dataframe.loc[(dataframe[day_column]>90) & (dataframe[day_column]<=180), rating_column].mean() * tw3/100 + \
dataframe.loc[dataframe[day_column]>180, rating_column].mean() * tw4/100

# user based weighted average
user_based_average = dataframe.loc[dataframe[progress_column]<=10, rating_column].mean() * uw1/100 +\
dataframe.loc[(dataframe[progress_column]>10) & (dataframe[progress_column]<=45), rating_column].mean() * uw2/100 +\
dataframe.loc[(dataframe[progress_column]>45) & (dataframe[progress_column]<=75), rating_column].mean() * uw3/100 +\
dataframe.loc[dataframe[progress_column]>75, rating_column].mean() * uw4/100