This video describes the differences between standard deviation and the standard error of the mean, and how they can be used to interpret data when the values are plotted as error bars on a graph.
Пікірлер: 235
@his1987 жыл бұрын
Thank you very much for this video! I can't imagine a more clear explanation
@PiersSupport7 жыл бұрын
Thanks Lena, I am glad you found it helpful!
@deeplearning25526 жыл бұрын
Kevin Piers what I don't understand is where does the number 6.33 at 4:18 come from? Standard deviation of a list of red-colored numbers (averages from 12 experiments with Jack, on 3:40), that is of [100, 101, 99, 114, 103, 101, 95, 99, 95, 105, 100, 93], is not 6.33 but 5.25. I've checked with Python with numpy, by hand, and using online SD calculators. All give population SD as 5.25 and sample SD as 5.48.
@Tyokok6 жыл бұрын
same calc results. asking too.
@KandMwedding5 жыл бұрын
it's because he has messed up a lot in this video. the s.d. of the first 5 trials listed for jack is 14.14 (not "16" as he claims later). and the SEM of *that* set is 6.32. so i assume that's what he was referring to with "6.33." ..as for the rest of the video, it's also not a very good explanation of a simple concept: i.e. that you can have quite variable data (say flipping a coin and calling heads "0" and tails "1") which could have a large s.d. no matter how many times you measure it (for the coin example it will approach 0.5 as the number of random flips grows), but nevertheless the uncertainty in the mean itself (represented by the SEM) will tend toward zero as you make more and more measurements, irrespective of how noisy those data are. the video could've used a better example (for instance, a person running anywhere is not a good example of independent data, as there could be trends in either direction -- faster or slower -- depending on the time between trials; thus these data are not even appropriately lumped together like this) and as you point out, he could've at least double checked his math before posting.
@winvictorywin56124 жыл бұрын
Piers Support Hello sir, I am having airborne dust concentrations data as PM10, PM2.5, PM 1 . These data was taken before and during dust producing work in a civil construction site. N=5 How can i compare these before and during operations data ? It seems that there is percent variation in dust concentrations in atmosphere between before and during operation data based on particle size. Before operation: PM 10 ( particle size less than 10 microns) is sharing 40% of total airborne dust, and PM 2.5 ( particle size less than 2. 5 micron) shares 10% of total airborne dust. During machine operation: PM 10 shares 60% and PM 2.5 10% only. It seems that PM 10 share is increased due to that machine operation? Which test is suitable for analysing these type similar data for discussion ? How to use statistics? Any comparison among these particle sizes? thank u.
@davidrosen51374 жыл бұрын
Four semesters of graduate level statistics, and you accomplished in 10 minutes what four different profs failed to accomplish at all. Thank you!
@katomoon61702 жыл бұрын
No better explanation than this one. Can't thank you enough Dr. Piers. You're an exceptional instructor with the ability to clearly, precisely and simply explain very complex statistics topics. God bless you. Much appreciation from Uganda - East Africa.
@quintonwilson85654 жыл бұрын
This is thee single best video on this subject on YT, thank you Dr. Piers.
@vikkirossiter2 жыл бұрын
I'm doing a stats class now and I understand more from this 10 minutes than the whole lecture on it. Much thanks
@SmokeyHooder Жыл бұрын
Watched this three times and finally I understood this. The best explanation I have found on this topic, no doubt!
@futurefee1444 Жыл бұрын
Excellent breakdown, thank you for your service.
@emmayu18477 жыл бұрын
This is the best statistics video I have seen. Such clear explanation and great presentation. Thank you!
@soknya11 ай бұрын
I need to watch it twice to confirm my understanding. Thank you for a clear explanation
@jessicafb53984 жыл бұрын
Thank you for explaining this concept so clearly and with great humor. Very helpful and enjoyable!
@akshu2515 жыл бұрын
Sad that I watched it too late. But as it is said, better late than never. Amazing video. Now, I will never forget the difference. Thank you.
@912sonic5 жыл бұрын
I'm glad I found this too. Better late then never honestly
@wilsonvuong88555 жыл бұрын
This is without a doubt the clearest video on SEM. Thank you so much for your efforts.
@NiekVink4 жыл бұрын
agree!
@neerajrokaya1132 Жыл бұрын
subscribed just after seeing this video..cant explain how aewsome this explanation is
@jamesrobertson91497 жыл бұрын
This is a brilliant video because it makes clear what the SEM is. first class! thanks.
@aziziqbal27774 жыл бұрын
Most clear explanation on this topic I have seen on youtube. You've earned yourself a subscriber.
@genevieveperdue80197 жыл бұрын
Thank you so much, this is a wonderful tutorial. I am a TA for a data analysis course and was having the hardest time figuring out how to emphasize the difference between SD and SEM. You did it very clearly and simply!! You just saved my students from a very confusing lab explanation :)
@PiersSupport7 жыл бұрын
Thanks for the positive comment Genevieve! I'm glad you found it helpful.
@cajogos4 жыл бұрын
Really good refresher to these statistics ideas, I had completely forgotten what standard deviation and SEM was! Thanks a lot!
@p_mouse8676 Жыл бұрын
I always explain it this way to students. SD is a measure of how big the spread is between samples. SEM is a measure how exact we know the average (or mean). It starts to get interesting when SD is relatively big. At that point one could argue how valid the test actually was. Because it's perfectly possible that the SD is very big (individual samples are widely spread) but SEM is quite small at the same time.
@user-pv5lg7hr1w6 жыл бұрын
You are a very good teacher and that is very rare nowadays.
@chitritaghosh42797 жыл бұрын
Thank you very much for the video. I am a medical student. I needed a understanding of the difference between SD & SEM for community medicine. Your video helped me a lot...
@michellexhg60779 ай бұрын
finally the video that answered all my questions! good job and thank you 💪🏼
@dr.renupoonia53373 жыл бұрын
very simple but effective way to teach these two terms and their use. Thanks a lot.
@sarahbronte30437 жыл бұрын
that's is really a simple access to the two complex concepts, thanks, that's really helpful for the psychology student without a math background to understand. you really knows what we are confusing in each steps.
@devong47226 жыл бұрын
You have a gift. Needed to brush up on a few of these for a class and this was concise yet coherent. Thank you so much!
@ramzyhedia1277 Жыл бұрын
Thank you very much for taking the time and effort to prepare this is a really very interesting and useful video. God bless you
@josephinetityiwe44346 жыл бұрын
Thank you very much for enhancing my understanding of SD and SEM.
@cbrewster103905 жыл бұрын
THANK YOU. I have consulted 10+ sources trying to figure out the difference and was beginning to feel like a complete idiot until you.
@ayabulelamkutswana2110 Жыл бұрын
watching this and I have a submission in two days, really helped thank you Doc!
@cindybokish15342 жыл бұрын
Thank you! Appreciate you taking time to explain. I cannot say how much this helped me.
@miladiouss4 жыл бұрын
You create intuition, something that other videos don't.
@andrewlukkuz3694 жыл бұрын
Thank you for making this video, I have a chem quiz on this and for some reason I couldn't wrap my head around the subject, your video helps alot bro.
@dinglixi51794 жыл бұрын
This solves my question which bothers me for so long. Thank you so much!
@manikant1990 Жыл бұрын
Excellently explained, please make more videos of these sort in statistics and any other topic. :) Great job again!!
@lensmaticoptical40835 жыл бұрын
Thank You Sir. It is a best explanation ever i have seen on this topic. Amazing... God bless you.
@NiekVink4 жыл бұрын
Finally a clear video on SEM, this helped a lot. Thanks!
@subramaniank63603 жыл бұрын
Clear explanation of standard error mean
@prakash_kp30394 жыл бұрын
Thats a great , concise and holistic video.
@JaqulinePrabu76 Жыл бұрын
Unreasonably good...great presentation!!
@jonelabutyte66172 жыл бұрын
very good and quick refresher of SD and SEM evaluations❤ Thank you!!!
@okiwahboris15976 жыл бұрын
Thanks for the video, i really understood much today, and i am defending my DVM tomorrow. God bless you
@THE______TRUTH7 жыл бұрын
idk why but I laughed at the example of examining the data of Jack and jill who ran up the hill.
@troberson55017 жыл бұрын
Thank you for explaining the significance of SD and SEM as it relates to data interpretation. I had plenty of definitions and calculations but no explanation, until now, about what those concepts are telling me about the data I'm looking at.
@KajiAwaley7 жыл бұрын
Yes data interpretation is more helpful from this video. Thank u Kevin
@luisborgesjr5 жыл бұрын
This man really knows his stuff!
@belal74904 жыл бұрын
Thanks very much Dr. Pier for your efforts. This is a very useful video.
@amosbako39812 жыл бұрын
Thank you for this video, it's a must-watch for statistic student
@Selorm4christ3 жыл бұрын
Thanks very much. This info is statistically a life challenger.
@logjonbudha1377 жыл бұрын
This video is most important for the understand of S.D.& S.E .Thnku so mush sir!!
@dreamliner7076 жыл бұрын
That explanation was so clear. Thank you.
@aceplusplusplus76523 жыл бұрын
Thank you Dr Piers!
@user-uh9gg5dc5k8 ай бұрын
GRACIAS!!!! Well done! Clearly and cleverly stated.:)
@movement91923 жыл бұрын
Excellent explanations of sd and adm
@yaswanthbangaru91164 жыл бұрын
An Incredible way to put it!
@MDMAx2 жыл бұрын
Thank you for the clear explanation!
@argytzak5 жыл бұрын
I used R to calculate the standard deviation of the averages and got 5.484828 (instead of 6.33 that you show). Note that the sd() function is R uses denominator n - 1. Why the difference?
@mohammedalqahtani26434 жыл бұрын
Truly you made it so simple and easy, Thanks!
@dheerajvarapana11242 жыл бұрын
Fantastic explanation. Thanks a lot for your time and help.
@RobvanMechelen4 жыл бұрын
Excellent explanation! my compliments. However when you mentioned Jacks 12 trials, The Mean of the 12 means = 100.20 and SD = 5.48. The SEM = SD/ sqrt(12) = 1.58, whereas you mention 6.33
@matthewx21052 жыл бұрын
That's ture, my final result is 5.48 as well. I'm quite confused about 6.33...
@Alex-fk3ni2 жыл бұрын
"The Mean of the 12 means = 100.20" - where did you get this number? The mean of 12 means is 100.42
@zhongdasun87722 жыл бұрын
the SEM is just the calculation of the STD of the mean of that 12 numbers, which means you do not have to /sqrt12. so the SEM is 5.48 as Mattew mentioned below.
@zhongdasun87722 жыл бұрын
@@matthewx2105you are correct
@RobvanMechelen2 жыл бұрын
@@zhongdasun8772 Thanks
@Mamatin24 жыл бұрын
This was so great! Thank you, Dr. Pierce!
@ozgekrklk47184 жыл бұрын
he is explaining very well , thank you
@rebekahcook94877 жыл бұрын
Super helpful video and very well presented. I just needed an overview and Jack and Jill were a helpful way to do it. And thanks for the coffee bag image ... that totally distracted me ... in a good way!
@PiersSupport7 жыл бұрын
Thanks for the feedback Rebekah - glad you liked it (and the coffee :)
@harikishanbusa4714 Жыл бұрын
Best explanation! much thanks.
@rebeccagoldin7567 жыл бұрын
There is a slight error in your interpretation of the 95% confidence interval. You say that the error bar contains an interval that, if you were to repeat your experiment 100 times, would contain the average 95 of 100 times. Instead the confidence interval (indicated by the error bars) changes each time you repeat your experiment. The correct statement is that in 95 out of 100 times, the calculated error bars will contain the “true mean.” This is true for both SEM and for SD. Otherwise, a truly excellent explanation with great graphics!
@PiersSupport7 жыл бұрын
Thanks for the clarification Rebecca!
@VaibhavYawalkar4 жыл бұрын
best video on this topic. Thanks a lot sir.
@brookesullivan66633 жыл бұрын
This was such a helpful video thank u so much
@minutetolearnit8449 Жыл бұрын
You are a legend sir 🙏
@adatse518494 жыл бұрын
Very informative and perfectly explained!
@nicholaskatto7 ай бұрын
thank you professor God bless you
@oliverbird83207 жыл бұрын
You explained so well on the concept!!!!!!!!!!
@pig_samurai6 жыл бұрын
You are my angel~ Mr. Kevin thank you!
@SaberNezumi6 жыл бұрын
A really good explanation. Thanks for the video.
@xuul73385 жыл бұрын
Great video! Thanks for sharing, this was clear and concise.
@mateom65964 жыл бұрын
what a lucid explanation. thank you.
@nandiniB112 жыл бұрын
Excellent explanation
@itssmsn915 жыл бұрын
Thanks for the video with such a nice explanation :)
@anirudhsood20062 жыл бұрын
Thank you so much for the video.
@noazamstein7 жыл бұрын
Awesome video! so clear and concise
@ritachaudhary57803 жыл бұрын
Thank you! Well explained
@altafalinaushad63686 жыл бұрын
SANTA MARIA!!! You saved my life!
@longjamboris10413 жыл бұрын
very helpful video. thanks again
@lesliehermann72672 жыл бұрын
That was SO helpful! Thank you!
@A_Box4 жыл бұрын
Hello. I was attempting to double check your work at 4:22 and I happen to find different results. Using Excel, the sample standard deviation for the set of averages is 5.483 and the population sample deviation is 5.250. Is this indeed a mistake or am I missing something?
@TonyTorzido6 жыл бұрын
I came here for STAT 300. Now I'm back for Ecology lol. Thanks, Sir Piers!
@MrEndocytosis7 жыл бұрын
Nice video thanks! Would you say in general that when a single person does the same test repeated times (person running a mile 5 times) you should show SEM but when you have a group of people that do the same test such as a team running a mile, then you show the SD?
@ansariarbaz33743 жыл бұрын
Just superb❤️❤️🔥🔥
@lllMrKrobylll7 жыл бұрын
Very nice and clear video. Thanks a lot!
@disha3558 Жыл бұрын
I would have topped in maths if I had found you sooner. 😅
@benlee35457 жыл бұрын
Hi Kelvin, are you able to show how you calculate SEM=6.33? I tried to compute but my answer is about 5.5.
@PiersSupport7 жыл бұрын
HI Ben. By golly it appears you are right. I put the values into the spreadsheet and got 5.48. Thanks for picking this up and sorry for any confusion!
@benlee35457 жыл бұрын
Thank you very much. This video is really friendly even for beginner who knows nothing. You really know understand the beginner difficulty. Thumbs up for you. :]
@danielpavon96235 жыл бұрын
THANK GOD SOMEONE ASKED THIS, I was going crazy. I too copied the averages of those 12 trials into Excel, calculated STDEV.S and got 5.48.
@baransakallioglu3 жыл бұрын
In calculations, everything seems to be rounded. For example 5:15 actual stdev is 15.81 but rounded up to 16. 16 / sqrt(5) = 7.155417527999327 and rounded up to 7.16 etc.
@jeranrai34883 жыл бұрын
please help me, really dont know how and where to take in the class for Applied Data Science Module that i was accepted from, when i login the worldquant university portal than it only prompts for the Master degree registration
@dzb337 жыл бұрын
I know Dr. Piers says he doesn't care about how we know that 95% of the probability lies within 2 SDs of the mean in a normal distribution, but it's actually really simple. Take an integral from -2 SD to 2 SD of a normal (or Gaussian) distribution. Anyone who's worked with probability distribution functions should be familiar with doing things like this, since you integrate the probability distribution function to calculate probabilities (indeed that's what we're doing here) or cumulative distribution functions.
@ph3124wr5 жыл бұрын
Many thanks, Dr. Pierce. I have learned a lot. I hope I can give you two thumb-ups.
@joshbridges47196 жыл бұрын
Thanks for the video. It was extremely helpful! My only question concerns the interpretation of the two graphs at the end of the video where they either completely overlap or don't overlap at all. You stated this means there is either no difference between the two populations or there is a difference. Could you clarify this point? Does it suggest that (in the first graph), it doesn't make a difference whether you watch the videos or not whereas with the last graph, there is an impact, on say, a student's grade?
@PiersSupport6 жыл бұрын
That is certainly a good summary of the graphs as far as I understand it. There are probably more nuanced interpretations, but that is a good working model. Cheers.
@joshbridges47196 жыл бұрын
Kevin Piers Thank you for your response. It helps clear up some things.
@Ferenczi69Aron5 жыл бұрын
I appreciate the simplicity of the explanation, but how is it that when I calculate stdev of the averages in red (from 3:50) using Excel's function STDEV.S, I get 5.48 and not 6.33?
@sexyaki7045 жыл бұрын
Ferenczi69Aron try STDEV.P
@hyacyn_th2 жыл бұрын
this guy is amazing
@ZhigaZhega7 жыл бұрын
Thanks man, most helpfull explanaton on you YT.
@gehuishen54155 жыл бұрын
Very clear explanation!
@benstolman40733 жыл бұрын
Best video out there
@taladiv34157 жыл бұрын
Nicely clear explanation of the two concepts. Keep up the good work :)
@quanzhaohe12217 жыл бұрын
Very clear explanation! Thank you!
@cicinindivin36892 жыл бұрын
±2 SE is 95% only for infinite measurements, if not is ± t student (2 tails) for n-1 observations/items