Statistics for Research - L11 - What are Outliers and How to Solve the Issue using SPSS?

The session discusses the basic concept of Outliers, How to check the outliers in SPSS, and How to solve the problem of outliers.
How to Deal with Outliers in R
• Statistics for Researc...
Do you have any questions, tips, or ideas? Let me know in the comments section below!
About:
Research With Fawad is a Research initiative to help young and early career research learn the research tools and techniques. It is an initiative to share research knowledge and help researchers learn to research the easy way.
Learn more about Research With Fawad at www.researchwithfawad.com.
#SPSS #Outliers #SolveOutliersIssues

[@sohailaftab4209]

Jazak Allah.

[@researchwithfawad]

Thanks for watching.

[@ahmedabdulahimahamud3272]

Perfect explanation, thank you very much

[@researchwithfawad]

Glad it was helpful!

[@mahmoudfaouzichaoubi5855]

Thank you = شُكراً

[@researchwithfawad]

Thanks. I am glad you liked it.

[@kamilaammar2310]

many thanks, may i have a reference to justify keeping outliers based on z score

[@researchwithfawad]

Pleasure. I am glad you liked it. Here is the reference
Statistics for Research Students: An Open Access Resource with Self-Tests and Illustrative Examples by ERICH C. FEIN; JOHN GILMOUR; TANYA MACHIN; AND LIAM HENDRY, UNIVERSITY OF SOUTHERN QUEENSLAND TOOWOOMBA

[@chantellewong1952]

Thank you very much for your tutorial. May I know if +/-3.3 the magic number? I have seen some said 2 some said 3. May I know if you have a reference to it? Thanks a bunch!

[@researchwithfawad]

Thanks for watching. Here is the reference for outliers.
Based on the recommendation of Fein et al. (2022), outliers were assessed using the Standardized (z) scores. A total of ......….. responses were outside the acceptable z score (+/-3.3) (Fein et al., 2022). The responses outside the acceptable threshold were removed from further analysis.
Fein, E. C., Gilmour, J., Machin, T., & Hendry, L. (2022). Statistics for Research Students: An Open Access Resource with Self-Tests and Illustrative Examples. University of Southern Queensland.

[@chantellewong1952]

@ResearchWithFawad Thank you very much Sir!

[@MsSaddal]

Sir I used standardized z value..I got some values in minus sign.. should I remove above -3??

[@researchwithfawad]

Remove over +/-3.33

[@MsSaddal]

@@researchwithfawad thankyou so much for your instant reply

[@buzztutorials]

Nice👍❤

[@researchwithfawad]

Thanks for the visit

[@mansoralzahrani2926]

Should I consider checking outliers with Likert data? And how? Please provide a reference to refer to. Thanks.

[@researchwithfawad]

Yes with Likert Scale data. For reference
Based on the recommendation of Fein et al. (2022), outliers were assessed using the Standardized (z) scores. A total of ......….. responses were outside the acceptable z score (+/-3.3) (Fein et al., 2022). The responses outside the acceptable threshold were removed from further analysis.
Fein, E. C., Gilmour, J., Machin, T., & Hendry, L. (2022). Statistics for Research Students: An Open Access Resource with Self-Tests and Illustrative Examples. University of Southern Queensland.

[@mansoralzahrani2926]

@@researchwithfawad Thanks!
Do I have to do it even if I will use SmartPLS for SEM-PLS? and why?

[@researchwithfawad]

Yes it is process of cleaning the data.

[@alittlefishhh]

jazakallahu khair, but may i ask you a question. i checked my data, which is total scores of a scale used on my psych research.
i followed your guide,
1. checked the boxplot, but there is no star/circle outlier,
2. but when i check the frequencies, 22.5% of my data is on the highest quartile
3. checked the histogram, but my data is not showing bell-curve you normally found on normal distribution data
4. checked for the z-score (standardised score), but all of the value is in range of +/- 3.3 (highest is +1.32, there are 25 data out of 109 total that has the EXACT same value;
while the lowest is -1.9, there are only 2 data out of 109 that has the exact same value)
do you think i should transform my data? please guide me :(

[@alittlefishhh]

and to add more context, when i analyze my second variable. the data is normal:
1. the histogram is kinda bell-curved in the middle
2. the highest and lowest z-score is +2, and -2 (its all different, unlike the first variable above)
3. and the significance value is >0.5
4. no outliers on boxplot

[@researchwithfawad]

Thanks for watching. Even if one of the techniques shows no outliers, that can be enough for further analysis.

[@rhafi2201]

Assalamualaikum brother, if i have 495 samples, would trimming 100 outliers is okay? Thankyou very much

[@researchwithfawad]

WAS. It is slightly on a higher side. But still if the remaining sample meets the minimum sample size criteria, you are good to go.

[@rhafi2201]

@@researchwithfawad thankyou very much for the reply brother. May i ask again if it's okay. How much is too much regarding trimming the outliers and how much is enough.

[@maazsatti5427]

Multivariate outliers?

[@researchwithfawad]

Hopefully soon I can do a separate video on it

[@Grace-bz3px]

Why looking the outlier from min and max value? and why value 16 is an outlier even its within the range ?

[@researchwithfawad]

Thanks for watching. Please refer to
Based on the recommendation of Fein et al. (2022), outliers were assessed using the Standardized (z) scores. A total of ......….. responses were outside the acceptable z score (+/-3.3) (Fein et al., 2022). The responses outside the acceptable threshold were removed from further analysis.
Fein, E. C., Gilmour, J., Machin, T., & Hendry, L. (2022). Statistics for Research Students: An Open Access Resource with Self-Tests and Illustrative Examples. University of Southern Queensland.

[@Grace-bz3px]

@@researchwithfawad does it mean its the IQR X1.5 = Outlier value?