I was going to turn in my science project without a t-test because I couldn't figure out how o do it. Friends were trying to help me and I still couldn't understand. I thought about TH-cam. Dude really saved my life. Explained everything. Thank you so much
Really clear instruction. Thanks for taking the time to do this tutorial for us. There are many, many statisticians who seem to enjoy making the subject inaccessible. Whoever put the help together for MS Excel is a sadist.
I hope you all find this video useful! If you have any questions, please do drop me an email. And if the video has REALLY helped and you want to buy me a beer, please see www.paypal.com/donate/?hosted_button_id=L692FVF8PNUKU
Hello Mr. Grange, My name is Celio, I'm from Brazil. And I spent hours searching for an easy and practical solution in Brazilian sites. And I just saw your video and solve my problem with statistical data analysis. Thank you and the video is great!
We have to do several experiments and labs at school that require to find the p value in excel, and I have used this video several times to help me find it each time. It's so clear and it so easy to understand! I searched for hours trying to find an easy way to understand how to find it and couldn't find one until I found this video. Thank you so much for it! It literally has saved me (and my grade)!
Okay I know it's been 9 years but thank you so much for this video! I was freeking out couse my teacher couldent explain it in a way that made sense to me but this was so easy! it kinda helped my final exams a lot
This is extremely simple and helpful. Where I trip up is when all the books say "we reject the null hypothesis" or similar instead of saying "This means these are different significantly" or similar. I reach the end and I'm thinking "What was the hypothesis again?" This is what youtube stats is good for. Thanks!
This has been a great help to me. It is now very easy to get a "p" value from the "t" test. I have developed a "one-tail" test proposal for myopia prevention from your analysis. Thanks!
It was such a great pleasure to watch your video. Wonderful clarity. You would not want to give up your day job but you would be a star with the BBC World Service with your superb communication skills. Many many thanks. Best wishes.
I so appreciated this video. I have no stats background and do not need the "full math" explanation for what I need to do, and this was perfectly clear and concise!
Hello Jim! An urgent question: is the result of this test via excel is the t-value or the p-value? And how do I see these two separately, if possible? Many thanks!!! Sharon
The E-106 means that you have to move your decimal place to the right 106 places. So your P value would be VERY small eg 0.0000000000000000000... ect. Your data is significantly different :) Hope this isnt too late!
Thank you so much! This was super easy to follow and made it easy to understand even though it's been a while since I took stats. Thank you again! Life saver. :)
Jim, I am currently doing my dissertation on how carbohydrate intake effects blood glucose. Can I first of all compliment you on the efficient and easy to understand video on t-test's. This is often an area of confusion for my peers (me included). I have just shown this to the majority of the class, all of which will be using to do their t testing along side SPSS. Thank you
Thank you for uploading all these videos. Great work and very helpful. I have watched your video on t-test. At some point you are saying that we need to decide whether we have the same variances between the 2 groups and I believe that you are saying that this is explained in another video. Could you please refer me to that video? Can we find out by using excel? Would this have anything to do with Levene's test? Thanks again, Athina.
Great video, one question: what if my dataset is imbalanced and I have more than 5 times the amount in one vs. The other? I guess since it uses averaged valued it wouldn't matter but, can you do it?
Thank you very, very much. It's probably a very easy thing for you, but it was actually very confusing for me until I watched your video. I have a question, though, if you'll excuse me: If I already have the means, SD-Variance and such descriptive results, can I still compare the means just by using them without the actual measurements for each, say, individual?
You probably know this by now but for others who may not: when you have '#####' in a cell in excel it is often because the cell is not big enough to show all the digits. A solution would either be to expand the cell or to make it stop at fewer decimals
Hi, great video! I’m wondering if you could help me. I’m trying to conduct a t-test to see if a lay betting strategy is worthy or not, I have the 1. Prices of each individual bet 2. Prices of winners. 3. Prices of losers 4. Average price won. 5.average price lost, however, I am struggling to know where to put each piece of data and if it’s the correct data to use. Thanks in advance 👍
I tried your method with different tails/types as well as calculated mine in paper, the excel methods ended up with a different value each time T^T the video is good thanks
Remember Excel is just giving you back the exact p-value. When you do the calculations on paper you are likely calculating the exact t-value (which is quite different). That might explain the differences you are getting.
Hi. I want to perform a T test. One of the values in the sample is very large. Should I omit it when I calculate mean, standard deviation and variance?
@DarthHako Yes, you can. The exact formula to use changes with whether you intend to test a between-subjects design or a within-subjects design. For a whithin-subjects design, your t-value = D_xy / (sdD_xy / (sqrt(n)). This looks complex, but D_xy refers to the difference between condition x and condition y, sdD_xy refers to the standard deviation of these differences, and sqrt(n) is just the square root of the number of observations you This website explains it better than I can: have.www.unt.edu/rss/class/Jon/ISSS_SC/Module008/isss_m8_introttests/node3.html
I'm not sure you'll answer my question in time (or at all) but I'd like to do a t-test to compare the mean of a group to the value that correspond to what they would have obtain if they've answered randomly so it would be a t-test comparing a mean based on real data and a pre determined mean, can you do that with excel? (i'm not sure if this was clear enough to understand, I hope so...)
I am doing my bachelor thesis and I am testing 2 trading strategies. One is an active and the other a buy and hold. The active strategy by and sell the stock when you have trading signals from technical analysis and the other just holds the stock. We have the returns and we think we should calculate the monthly returns and then compare the two strategies in a t-test. Is that right? You have both a sample t-test with known or unknown variances but then you also have a paired t-test.
+Per Forsberg It depends what unit of measurement your returns are in, but it sounds OK. Yes, a t-test sounds like it will be appropriate. Your values are coming from different groups, so it would be an independent t-test, not a paired t-test.
Excellent! My question, once I have a p-value (result of the t-test) what is the next calculation to determine whether improvement has occurred between two groups of data?
Your p-value is essentially a percentage value. (1 - p-value)*100 = percent chance the difference between groups is statistically significant. A p-value ≤ 0.05 is the gold standard in industry as it indicates your group is 6-sigma from the mean (3-sigma to the left & 3-sigma to the right), which means you can be 95+% confident that your groups are statistically different. Your target p-value can be adjusted depending on how confident you want to be in reporting your groups to be different. Check out Khan Academy for more in depth videos on this topic.
I have a question. You mentioned that the resulting value is the probability/p-value. is it also correct to call that the t-value? My worksheet wants me to list the "t-values and probabilities". I thought t-values and probabilities are the same thing.
Jim. Until seeing your video I had assumed that using the =ttest command gave you a t-stat which you then had to compare to a p value table. Can you explain why this is not the case and what the value you refer to as the p value actually is please?
***** Hi. I do not know why that is not the case. You would have to ask the designers of Excel why :) The p-value is the probability of observing a test statistic (not shown by Excel) as extreme (or more so) as the one you have observed, if the null hypothesis is true. So, a low p-value means that there is a low probability of observing a test statistic as extreme as you have if there is no difference in reality. People believe by reverse inference that a low p-value implies there is a greater likelihood the difference in your data is a real, "significant" difference.
Hi Jim! I have a group of 58 students 22 of which are female and 33 male. I want to test if there is a statistically significant difference between the the internet use perceptions, practices of male and female students. by doing so, i want to check whether or not gender is a factor affecting students internet use. Of the three types of t-test, which type should i use and why. some points about the sample: they are 2nd year students at a university,all from the same faculty of humanities, it is null hypothesis.
Thanks so much! A question, what if I want to test whether values in an array (they are in fact simulated values) are statistically significant from a particular actual value?
Hi, let's say I have data for pre and post tests.... all i need to do now is to just analyse the two groups' post tests right? As in the data that i need to insert into that two columns are the post tests for both groups right?
Sunitha Rachel Hi - no, you would likely need to take into account the pre-test scores, too. This can be done using a factorial ANOVA, with one factor being "time" (i.e., pre & post test), and another factor for your groups (group 1 & group 2). More correctly, you would likely need to conduct an Analysis of Covariance (ANCOVA), which allows you to control for the difference pre-test.
What if I had two columns of consumer age and another row of the purchase amount, and I wanted to see if there was a correlation between the two, which t-test would I use
You would use the =CORREL(range1, range2) function, where range1 is your ages and range2 is your purchase amount. This returns a pearson's r value (between -1 and 1)
@JimGrange. Thanks for that Jim, also how would I go about getting a sample of age ranges from my mass of data so I can do another T-test ? I can't seem to find the answer online
With regards to the final values....does excel provide the value based on the critical value table for a t-test or does the 0.1672 result then need to be referred to the critical value table at 0.05 (df=7) in order to reject the null hypothesis??? Thanks
+Grant Ormerod gspo13@hotmail.com Hi Grant - the result returned by Excel is *not* the t-value, it is the exact p-value. Normally you would check the t-value you obtain with the critical values in a textbook to see whether your p-value is < 0.05. However, as Excel is providing the exact value you need not do this. In this case, your value is p = 0.1672, so your p is not less than 0.05.
Working on my data analysis now and I already calculated the mean for 2 groups I want to compare but excel tells me I can't just select the calculated mean. So we can only select a list of values from which it will calculate the mean?
Since you're looking at a 1-tail t-test, wouldn't your target p-value be 2.5? In either case, your conditions would be statistically different, but a p-value of 5 refers to 6-sigma testing. A 1-tail t-test is only interested in a single direction, therefore 3-sigma from the mean.
Hi Jim, Great video - thanks for posting. At 0:55 you mention that the related / paired t-test is the test to use if the variables come from the same participant. What method should be used if the data is from separate participants? Say each variable is from a different person and nobody contribute to both Condition A and B. Many Thanks.
I was going to turn in my science project without a t-test because I couldn't figure out how o do it. Friends were trying to help me and I still couldn't understand. I thought about TH-cam. Dude really saved my life. Explained everything. Thank you so much
+Deandre Mathurin My pleasure!
Really clear instruction. Thanks for taking the time to do this tutorial for us. There are many, many statisticians who seem to enjoy making the subject inaccessible. Whoever put the help together for MS Excel is a sadist.
The most understandable video about t-test I have found. Thank you very much for help!
hello can i ask you question ?
@@redsem9712 sure
I hope you all find this video useful! If you have any questions, please do drop me an email. And if the video has REALLY helped and you want to buy me a beer, please see www.paypal.com/donate/?hosted_button_id=L692FVF8PNUKU
Jim Grange i donot get the right answer. After closing the brackets which key is to be pressed??
enter
all my life ive been looking for an app that has TTEst without knowing it is just right there in EXCEl, thank you very much for sharing this one...
This really save our research as well as our future :)
yes. It helped (y)
Six years later and this is helping me dearly with my high school advanced scientific research class, thank you VERY much.
God damn I love when stuff like this is explained clearly and concisely, thank you sir!
+Archie Farrer Thanks Archie!
So concise and straight to the point. I found my favorite stats tutor.
Hello Mr. Grange,
My name is Celio, I'm from Brazil.
And I spent hours searching for an easy and practical solution in Brazilian sites. And I just saw your video and solve my problem with statistical data analysis.
Thank you and the video is great!
We have to do several experiments and labs at school that require to find the p value in excel, and I have used this video several times to help me find it each time. It's so clear and it so easy to understand! I searched for hours trying to find an easy way to understand how to find it and couldn't find one until I found this video. Thank you so much for it! It literally has saved me (and my grade)!
I'm very pleased you found it of use!
This is the best explanation I've found to describe a t test. Thank you!
Much appreciated. Elegant and simple, as well as easy to understand. Well done and thank you!
3AM in the morning couldn't find a better video than this.. Thank you for the video!
It's the best on the interwebs! Fact!
To the point and concise explanations make your videos the most favourite
You can't imagine how usefull it is ! I din't undertand ma university homework and you did it in 5 min.
Okay I know it's been 9 years but thank you so much for this video! I was freeking out couse my teacher couldent explain it in a way that made sense to me but this was so easy! it kinda helped my final exams a lot
Glad it helped!
This helps me a lot. Thank you so much😭 I've been struggling to do the t-test but after I saw your vids... I understand it now.😭❣️
I appreciate this Jim! You just helped a Gifted and Talented Department in a school district in Northern Nevada!
This is extremely simple and helpful. Where I trip up is when all the books say "we reject the null hypothesis" or similar instead of saying "This means these are different significantly" or similar. I reach the end and I'm thinking "What was the hypothesis again?" This is what youtube stats is good for. Thanks!
You are the legend I been looking out for. wasted 2 hrs on web research. Thanks
This has been a great help to me. It is now very easy to get a "p" value from the "t" test. I have developed a "one-tail" test proposal for myopia prevention from your analysis. Thanks!
The numbers Mason, what do they mean?! - Call of Duty Black Ops
It was such a great pleasure to watch your video. Wonderful clarity. You would not want to give up your day job but you would be a star with the BBC World Service with your superb communication skills. Many many thanks. Best wishes.
You are too kind! Thanks for watching :)
This is the clearest I've heard it explained. Thank you
Had to watch the video several times but I understand this so much better now! thanks!
Very helpful information, we need more people like you in the world!
Thank you for sharing your knowledge in a simpler form. Very much helpful.
Thanks a lot, better than many other professors.
Thank you for the explanation! My genetics professor expected us to already know how to do this and did not explain it.
I so appreciated this video. I have no stats background and do not need the "full math" explanation for what I need to do, and this was perfectly clear and concise!
You are the man!! not only i know how to calculate t-test but you made me understand why it is!! you have saved me a lot of reading. Great job!! :)
Thanks a lot for the explanation, made otherwise a confusing topic easier to understand.
This is VERY GOOD. I had "forgotten" some of this - and your review was very valuable to me! Thanks!
Excellent. very easy to understand. now I can do my own t-test sheets and statistical mats on variables
Fantastic, ur video was on point and simple. 👍🏻
Hello Jim!
An urgent question: is the result of this test via excel is the t-value or the p-value? And how do I see these two separately, if possible? Many thanks!!!
Sharon
Hi Sharon - this is a p-value. Excel won't give you the t-value directly.
The E-106 means that you have to move your decimal place to the right 106 places. So your P value would be VERY small eg 0.0000000000000000000... ect. Your data is significantly different :) Hope this isnt too late!
Thank you ❤
Thank you so much! This was super easy to follow and made it easy to understand even though it's been a while since I took stats. Thank you again! Life saver. :)
Thank you very much! Your instruction is straight forward thus understandable, that helps me to solve my problem.
Jim,
I am currently doing my dissertation on how carbohydrate intake effects blood glucose. Can I first of all compliment you on the efficient and easy to understand video on t-test's. This is often an area of confusion for my peers (me included). I have just shown this to the majority of the class, all of which will be using to do their t testing along side SPSS.
Thank you
That is fantastic to hear, thank you so much for your kind feedback!
Thank you! This quick and easy tutorial helped me put theory into practice for my research project!
Thank you for uploading all these videos. Great work and very helpful. I have watched your video on t-test. At some point you are saying that we need to decide whether we have the same variances between the 2 groups and I believe that you are saying that this is explained in another video. Could you please refer me to that video? Can we find out by using excel? Would this have anything to do with Levene's test? Thanks again, Athina.
Hello can you add link to video assessing if there is equal variance that you reference in the video?
Thanks for the video. Short and to the point.
Thanks so much for this video, saved my life for a last minute presentation!
Thank YOU for the VERY clear video!
This is the best i cant thank you enough!!!
Greetings from a student form the Netherlands :)
Glad it helped! Cheers from the UK :)
Really fantastic video - I will be sharing this with all of my coworkers, it helped immensely!
Wow, that's great! Thanks!
Fantastic video! My SPSS license from school ran out so I had to use excel, this video was very helpful :)
Thankyou this has been stressing me seemed so complicated 😂🙏
Very simple and clear explanation! Thank you so much
My pleasure - glad you found it of use!
You have saved lives today
Thank you for the simple explanation. This has helped me greatly
Thank you, This was very useful and well explained.
thank you for the instructional, informative, and concise video. it really helped me a lot.
you taught me more than my teacher.
Great video, one question: what if my dataset is imbalanced and I have more than 5 times the amount in one vs. The other? I guess since it uses averaged valued it wouldn't matter but, can you do it?
This was so helpful. Thanks a lot
Hi sir, like to ask about the problem I have. I have this 5 person having training records from day 1 and day 8 I would like to see what should I use?
Great help. Concise and clear.
Thank you very, very much. It's probably a very easy thing for you, but it was actually very confusing for me until I watched your video. I have a question, though, if you'll excuse me: If I already have the means, SD-Variance and such descriptive results, can I still compare the means just by using them without the actual measurements for each, say, individual?
You probably know this by now but for others who may not: when you have '#####' in a cell in excel it is often because the cell is not big enough to show all the digits. A solution would either be to expand the cell or to make it stop at fewer decimals
still relevant and very helpful, thank you
Hi, great video! I’m wondering if you could help me. I’m trying to conduct a t-test to see if a lay betting strategy is worthy or not, I have the 1. Prices of each individual bet 2. Prices of winners. 3. Prices of losers 4. Average price won. 5.average price lost, however, I am struggling to know where to put each piece of data and if it’s the correct data to use. Thanks in advance 👍
You saved my life! Thanks so much
I tried your method with different tails/types as well as calculated mine in paper, the excel methods ended up with a different value each time T^T the video is good thanks
Remember Excel is just giving you back the exact p-value. When you do the calculations on paper you are likely calculating the exact t-value (which is quite different). That might explain the differences you are getting.
thanks everything is sorted now :3
Hi. I want to perform a T test. One of the values in the sample is very large. Should I omit it when I calculate mean, standard deviation and variance?
@DarthHako Yes, you can. The exact formula to use changes with whether you intend to test a between-subjects design or a within-subjects design. For a whithin-subjects design, your t-value = D_xy / (sdD_xy / (sqrt(n)). This looks complex, but D_xy refers to the difference between condition x and condition y, sdD_xy refers to the standard deviation of these differences, and sqrt(n) is just the square root of the number of observations you This website explains it better than I can:
have.www.unt.edu/rss/class/Jon/ISSS_SC/Module008/isss_m8_introttests/node3.html
You saved my life! thank you so much - your video was so useful!!
I'm not sure you'll answer my question in time (or at all) but I'd like to do a t-test to compare the mean of a group to the value that correspond to what they would have obtain if they've answered randomly
so it would be a t-test comparing a mean based on real data and a pre determined mean, can you do that with excel?
(i'm not sure if this was clear enough to understand, I hope so...)
I am doing my bachelor thesis and I am testing 2 trading strategies. One is an active and the other a buy and hold. The active strategy by and sell the stock when you have trading signals from technical analysis and the other just holds the stock.
We have the returns and we think we should calculate the monthly returns and then compare the two strategies in a t-test.
Is that right? You have both a sample t-test with known or unknown variances but then you also have a paired t-test.
+Per Forsberg It depends what unit of measurement your returns are in, but it sounds OK. Yes, a t-test sounds like it will be appropriate. Your values are coming from different groups, so it would be an independent t-test, not a paired t-test.
Mind blowing video...thank you so much
Thank you for this!
Also can you read me a bedtime story lmao voice is beautiful!
really really great video!!!!!!!!! It helped me A LOT!!!!! THANK YOU!!!!!
Excellent! My question, once I have a p-value (result of the t-test) what is the next calculation to determine whether improvement has occurred between two groups of data?
Your p-value is essentially a percentage value. (1 - p-value)*100 = percent chance the difference between groups is statistically significant. A p-value ≤ 0.05 is the gold standard in industry as it indicates your group is 6-sigma from the mean (3-sigma to the left & 3-sigma to the right), which means you can be 95+% confident that your groups are statistically different. Your target p-value can be adjusted depending on how confident you want to be in reporting your groups to be different. Check out Khan Academy for more in depth videos on this topic.
Which test can be used if we have PH ranges from 2-6 used for citric acid production and we need to findout if its statistically significant or not?
Thank you so much this was really useful and easily understood!
I have a question.
You mentioned that the resulting value is the probability/p-value.
is it also correct to call that the t-value?
My worksheet wants me to list the "t-values and probabilities".
I thought t-values and probabilities are the same thing.
Jim. Until seeing your video I had assumed that using the =ttest command gave you a t-stat which you then had to compare to a p value table. Can you explain why this is not the case and what the value you refer to as the p value actually is please?
***** Hi. I do not know why that is not the case. You would have to ask the designers of Excel why :) The p-value is the probability of observing a test statistic (not shown by Excel) as extreme (or more so) as the one you have observed, if the null hypothesis is true. So, a low p-value means that there is a low probability of observing a test statistic as extreme as you have if there is no difference in reality. People believe by reverse inference that a low p-value implies there is a greater likelihood the difference in your data is a real, "significant" difference.
Hi Jim!
I have a group of 58 students 22 of which are female and 33 male. I want to test if there is a statistically significant difference between the the internet use perceptions, practices of male and female students. by doing so, i want to check whether or not gender is a factor affecting students internet use. Of the three types of t-test, which type should i use and why. some points about the sample: they are 2nd year students at a university,all from the same faculty of humanities, it is null hypothesis.
Teşekkür ederim bu güzel video için. Türkiye'den selamlar.
✌☮️❤🎸
Thanks so much!
A question, what if I want to test whether values in an array (they are in fact simulated values) are statistically significant from a particular actual value?
super video. very good practical help. Thanks.
thx you saved my exams :)
Hi, let's say I have data for pre and post tests.... all i need to do now is to just analyse the two groups' post tests right? As in the data that i need to insert into that two columns are the post tests for both groups right?
Sunitha Rachel Hi - no, you would likely need to take into account the pre-test scores, too. This can be done using a factorial ANOVA, with one factor being "time" (i.e., pre & post test), and another factor for your groups (group 1 & group 2). More correctly, you would likely need to conduct an Analysis of Covariance (ANCOVA), which allows you to control for the difference pre-test.
Thanks for the help :) Much appreciated :)
Superb 👍
What if I had two columns of consumer age and another row of the purchase amount, and I wanted to see if there was a correlation between the two, which t-test would I use
You would use the =CORREL(range1, range2) function, where range1 is your ages and range2 is your purchase amount. This returns a pearson's r value (between -1 and 1)
@JimGrange. Thanks for that Jim, also how would I go about getting a sample of age ranges from my mass of data so I can do another T-test ? I can't seem to find the answer online
@@rossl5908 Sorry I'm not sure what you mean?
Great help, cheers for the video!
Very Helpful presentation! thank you!
clear and brief! this is very helpful! thanks a lot!!
So based on the data used, which type is better 1, 2 or 3?
There is no "best", here. It depends whether your data (for each condition) come from the same participants or from different participants.
a fucking man i lovw you, i spent ONE HOUR LOOKING FOR SOMETHING THIS SIMPLE GOD THANK YOU I PASSED PSYCH BC OF U
With regards to the final values....does excel provide the value based on the critical value table for a t-test or does the 0.1672 result then need to be referred to the critical value table at 0.05 (df=7) in order to reject the null hypothesis??? Thanks
+Grant Ormerod gspo13@hotmail.com Hi Grant - the result returned by Excel is *not* the t-value, it is the exact p-value. Normally you would check the t-value you obtain with the critical values in a textbook to see whether your p-value is < 0.05. However, as Excel is providing the exact value you need not do this. In this case, your value is p = 0.1672, so your p is not less than 0.05.
Thanks, Great video, I used it for my degree students to help with some mock data. :-)
Working on my data analysis now and I already calculated the mean for 2 groups I want to compare but excel tells me I can't just select the calculated mean. So we can only select a list of values from which it will calculate the mean?
Correct - You cannot do a t-test just between two mean values. You need the individual data points
Excellent explanation, thank you very much!!!
very clear, looking forward to sharing with my students
thanks a million. so clear and precise
Since you're looking at a 1-tail t-test, wouldn't your target p-value be 2.5? In either case, your conditions would be statistically different, but a p-value of 5 refers to 6-sigma testing. A 1-tail t-test is only interested in a single direction, therefore 3-sigma from the mean.
Hi Jim, Great video - thanks for posting.
At 0:55 you mention that the related / paired t-test is the test to use if the variables come from the same participant. What method should be used if the data is from separate participants? Say each variable is from a different person and nobody contribute to both Condition A and B. Many Thanks.
Sorry for late reply - it would be an independent t-test. You need to enter "2" as the "type" in the equation. See at about 3:03 in the video.
great video! Very helpful for my work.
+joemike75 Glad it helped!