In this video, Dr. Kushner discusses the difference between a population and sample and breaks down two types of (probability) sampling: random sampling and stratified sampling.
You are an excellent instructor. You will go very far! I have watched any videos about this topic and still. I would end the video with the same dumb level of understanding as when I began the video. But when I stumbled across this version of the video, I had no other choice but to understand "Sampling Methods". I understand clearly the entire ramification from every introductory level aspect. thankssssssssss
Check your understanding: Administrators at Jones Elementary School surveyed a random sample of 100 of their fourth graders to see how they felt about extending recess time from 20 minutes to 30 minutes. Identify the population and sample in this scenario. A. The population is all students at Jones Elementary School; the sample is the 100 fourth graders surveyed B. The population is all fourth graders at Jones Elementary School; the sample is the 100 fourth graders surveyed C. The population is all fourth graders at Jones Elementary School; the sample is all the students at Jones Elementary School D. The population is all students at Jones Elementary School; the sample is all of the fourth graders at Jones Elementary School
Giving the example of Stratosphere (i.e. layers) to explain stratified sampling was so cool! It made the missing connection in my understanding! Thanks!
you teach in an amazing way sir, my concept is solid clear now. Literally spent ages looking for a good stats video since ive never studied the subject before and found this gold. THANKYOU! keep going!
Thank you so much because I'm struggling. I hope your channel continues to grow because you're doing a brilliant job! New subscriber...looking forward to more content.
I've watched this video so many times! =/ I’m having difficulty with my homework! I want to know if I am doing this right. Any feedback would be highly appreciated. An airline company would like to know the number of pieces of carry-on luggage (on average) on each flight. However, instead of looking at every flight, the airline company decides to take a sample of flights. 1. Describe a simple random sample to create such a sample. Population (N)- entirely of something- All flights Sample (n) - part of the population- select based on features and characteristics- first class, economy, international and domestic flights. In order to take a simple random sample of a sample of flights, we can select based on criteria mentioned above and use a computer random generator to generate random numbers. 2. Describe a stratified random sampling technique to create such a sample. In a stratified random sampling- the population of flights would be divided into different subgroups of the population (strata). Stratas are homogenous to themselves. In this case, each characteristic can be its own strata (first class, economy, international and domestic flights). All passengers who fly economy, would be placed in one strata or subgroup. All passengers who fly first class would be placed in its own strata. All passengers who have domestic flight, would be placed in another strata. All passengers who have an international flight, would be placed into another strata. After each strata is formed, we can take a random selection sample of each strata to ensure that every specific subgroup was represented, thus we can make better inferences about the population.
