1. Left vs. Department

## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## | Chi-square contribution |
## |           N / Row Total |
## |           N / Col Total |
## |         N / Table Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  14999 
## 
##  
##               | hr$left 
## hr$Department |         0 |         1 | Row Total | 
## --------------|-----------|-----------|-----------|
##    accounting |       563 |       204 |       767 | 
##               |     0.783 |     2.506 |           | 
##               |     0.734 |     0.266 |     0.051 | 
##               |     0.049 |     0.057 |           | 
##               |     0.038 |     0.014 |           | 
## --------------|-----------|-----------|-----------|
##            hr |       524 |       215 |       739 | 
##               |     2.709 |     8.670 |           | 
##               |     0.709 |     0.291 |     0.049 | 
##               |     0.046 |     0.060 |           | 
##               |     0.035 |     0.014 |           | 
## --------------|-----------|-----------|-----------|
##            IT |       954 |       273 |      1227 | 
##               |     0.391 |     1.252 |           | 
##               |     0.778 |     0.222 |     0.082 | 
##               |     0.083 |     0.076 |           | 
##               |     0.064 |     0.018 |           | 
## --------------|-----------|-----------|-----------|
##    management |       539 |        91 |       630 | 
##               |     7.250 |    23.202 |           | 
##               |     0.856 |     0.144 |     0.042 | 
##               |     0.047 |     0.025 |           | 
##               |     0.036 |     0.006 |           | 
## --------------|-----------|-----------|-----------|
##     marketing |       655 |       203 |       858 | 
##               |     0.002 |     0.008 |           | 
##               |     0.763 |     0.237 |     0.057 | 
##               |     0.057 |     0.057 |           | 
##               |     0.044 |     0.014 |           | 
## --------------|-----------|-----------|-----------|
##   product_mng |       704 |       198 |       902 | 
##               |     0.408 |     1.307 |           | 
##               |     0.780 |     0.220 |     0.060 | 
##               |     0.062 |     0.055 |           | 
##               |     0.047 |     0.013 |           | 
## --------------|-----------|-----------|-----------|
##         RandD |       666 |       121 |       787 | 
##               |     7.346 |    23.510 |           | 
##               |     0.846 |     0.154 |     0.052 | 
##               |     0.058 |     0.034 |           | 
##               |     0.044 |     0.008 |           | 
## --------------|-----------|-----------|-----------|
##         sales |      3126 |      1014 |      4140 | 
##               |     0.255 |     0.815 |           | 
##               |     0.755 |     0.245 |     0.276 | 
##               |     0.274 |     0.284 |           | 
##               |     0.208 |     0.068 |           | 
## --------------|-----------|-----------|-----------|
##       support |      1674 |       555 |      2229 | 
##               |     0.348 |     1.114 |           | 
##               |     0.751 |     0.249 |     0.149 | 
##               |     0.146 |     0.155 |           | 
##               |     0.112 |     0.037 |           | 
## --------------|-----------|-----------|-----------|
##     technical |      2023 |       697 |      2720 | 
##               |     1.178 |     3.771 |           | 
##               |     0.744 |     0.256 |     0.181 | 
##               |     0.177 |     0.195 |           | 
##               |     0.135 |     0.046 |           | 
## --------------|-----------|-----------|-----------|
##  Column Total |     11428 |      3571 |     14999 | 
##               |     0.762 |     0.238 |           | 
## --------------|-----------|-----------|-----------|
## 
##  
## Statistics for All Table Factors
## 
## 
## Pearson's Chi-squared test 
## ------------------------------------------------------------
## Chi^2 =  86.82547     d.f. =  9     p =  7.04213e-15 
## 
## 
## 

Technical Interpretation

  • The p-value is smaller than alpha (0.001), therefore we reject the H0 and conclude that there is a significant association between department and attrition.

Non-Technical Interpretation

  • Some departments have much higher turnover than others.
  • For example, employees in Sales compared to employees in Management are 6 (0.815/0.144) times more likely to leave.
  • Employees in Technical are 2 (0.256/0.144) times more likely to leave than employees in Management.
Graph 1

2. Left vs. Salary

## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## | Chi-square contribution |
## |           N / Row Total |
## |           N / Col Total |
## |         N / Table Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  14999 
## 
##  
##              | hr$left 
##    hr$salary |         0 |         1 | Row Total | 
## -------------|-----------|-----------|-----------|
##         high |      1155 |        82 |      1237 | 
##              |    47.915 |   153.339 |           | 
##              |     0.934 |     0.066 |     0.082 | 
##              |     0.101 |     0.023 |           | 
##              |     0.077 |     0.005 |           | 
## -------------|-----------|-----------|-----------|
##          low |      5144 |      2172 |      7316 | 
##              |    33.200 |   106.247 |           | 
##              |     0.703 |     0.297 |     0.488 | 
##              |     0.450 |     0.608 |           | 
##              |     0.343 |     0.145 |           | 
## -------------|-----------|-----------|-----------|
##       medium |      5129 |      1317 |      6446 | 
##              |     9.648 |    30.876 |           | 
##              |     0.796 |     0.204 |     0.430 | 
##              |     0.449 |     0.369 |           | 
##              |     0.342 |     0.088 |           | 
## -------------|-----------|-----------|-----------|
## Column Total |     11428 |      3571 |     14999 | 
##              |     0.762 |     0.238 |           | 
## -------------|-----------|-----------|-----------|
## 
##  
## Statistics for All Table Factors
## 
## 
## Pearson's Chi-squared test 
## ------------------------------------------------------------
## Chi^2 =  381.225     d.f. =  2     p =  1.652087e-83 
## 
## 
## 

Technical Interpretation

  • The p-values is smaller than alpha (0.001), therefore we reject thr Ho, and conclude that there is an association between salary and Salary level and attrition relationship is significant because the p-value is less than 0.001.

Non-Technical Interpretation

  • Employees with high salary leave much less.
  • Employees with lower salaries are 4.5 times (0.297/0.066) likely to leave than those with higher salaries.
  • Employees with low salaries are 3 times (0.204/0.066) more likely to leave vs. those with medium salaries
Graph 2

3. Left vs. Promotion in Last 5 Years

## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## | Chi-square contribution |
## |           N / Row Total |
## |           N / Col Total |
## |         N / Table Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  14999 
## 
##  
##                          | hr$left 
## hr$promotion_last_5years |         0 |         1 | Row Total | 
## -------------------------|-----------|-----------|-----------|
##                        0 |     11128 |      3552 |     14680 | 
##                          |     0.290 |     0.928 |           | 
##                          |     0.758 |     0.242 |     0.979 | 
##                          |     0.974 |     0.995 |           | 
##                          |     0.742 |     0.237 |           | 
## -------------------------|-----------|-----------|-----------|
##                        1 |       300 |        19 |       319 | 
##                          |    13.343 |    42.702 |           | 
##                          |     0.940 |     0.060 |     0.021 | 
##                          |     0.026 |     0.005 |           | 
##                          |     0.020 |     0.001 |           | 
## -------------------------|-----------|-----------|-----------|
##             Column Total |     11428 |      3571 |     14999 | 
##                          |     0.762 |     0.238 |           | 
## -------------------------|-----------|-----------|-----------|
## 
##  
## Statistics for All Table Factors
## 
## 
## Pearson's Chi-squared test 
## ------------------------------------------------------------
## Chi^2 =  57.26273     d.f. =  1     p =  3.813123e-14 
## 
## Pearson's Chi-squared test with Yates' continuity correction 
## ------------------------------------------------------------
## Chi^2 =  56.26163     d.f. =  1     p =  6.344155e-14 
## 
## 

Technical Interpretation

  • The p-value is smaller than alpha (0.001), so we reject the H0.
  • There is a statistically significant association between promotion history and employee attrition.

Non-Technical Interpretation

  • Employees who were not promoted in the last 5 years are 4 (0.242/0.06) times more likely to leave than employees who did receive a promotion.
  • Lack of career progression is strongly linked to higher turnover.
Graph 3

4. Left vs. Tenure

## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## | Chi-square contribution |
## |           N / Row Total |
## |           N / Col Total |
## |         N / Table Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  14999 
## 
##  
##                       | hr$left 
## hr$time_spend_company |         0 |         1 | Row Total | 
## ----------------------|-----------|-----------|-----------|
##                     2 |      3191 |        53 |      3244 | 
##                       |   209.353 |   669.977 |           | 
##                       |     0.984 |     0.016 |     0.216 | 
##                       |     0.279 |     0.015 |           | 
##                       |     0.213 |     0.004 |           | 
## ----------------------|-----------|-----------|-----------|
##                     3 |      4857 |      1586 |      6443 | 
##                       |     0.552 |     1.765 |           | 
##                       |     0.754 |     0.246 |     0.430 | 
##                       |     0.425 |     0.444 |           | 
##                       |     0.324 |     0.106 |           | 
## ----------------------|-----------|-----------|-----------|
##                     4 |      1667 |       890 |      2557 | 
##                       |    40.594 |   129.910 |           | 
##                       |     0.652 |     0.348 |     0.170 | 
##                       |     0.146 |     0.249 |           | 
##                       |     0.111 |     0.059 |           | 
## ----------------------|-----------|-----------|-----------|
##                     5 |       640 |       833 |      1473 | 
##                       |   207.268 |   663.303 |           | 
##                       |     0.434 |     0.566 |     0.098 | 
##                       |     0.056 |     0.233 |           | 
##                       |     0.043 |     0.056 |           | 
## ----------------------|-----------|-----------|-----------|
##                     6 |       509 |       209 |       718 | 
##                       |     2.647 |     8.472 |           | 
##                       |     0.709 |     0.291 |     0.048 | 
##                       |     0.045 |     0.059 |           | 
##                       |     0.034 |     0.014 |           | 
## ----------------------|-----------|-----------|-----------|
##                     7 |       188 |         0 |       188 | 
##                       |    13.986 |    44.760 |           | 
##                       |     1.000 |     0.000 |     0.013 | 
##                       |     0.016 |     0.000 |           | 
##                       |     0.013 |     0.000 |           | 
## ----------------------|-----------|-----------|-----------|
##                     8 |       162 |         0 |       162 | 
##                       |    12.052 |    38.569 |           | 
##                       |     1.000 |     0.000 |     0.011 | 
##                       |     0.014 |     0.000 |           | 
##                       |     0.011 |     0.000 |           | 
## ----------------------|-----------|-----------|-----------|
##                    10 |       214 |         0 |       214 | 
##                       |    15.921 |    50.950 |           | 
##                       |     1.000 |     0.000 |     0.014 | 
##                       |     0.019 |     0.000 |           | 
##                       |     0.014 |     0.000 |           | 
## ----------------------|-----------|-----------|-----------|
##          Column Total |     11428 |      3571 |     14999 | 
##                       |     0.762 |     0.238 |           | 
## ----------------------|-----------|-----------|-----------|
## 
##  
## Statistics for All Table Factors
## 
## 
## Pearson's Chi-squared test 
## ------------------------------------------------------------
## Chi^2 =  2110.08     d.f. =  7     p =  0 
## 
## 
## 

Technical Interpretation

  • The chi-square test gives a p-value below 0.001, so we reject the H0 and conclude that tenure is significantly associated with attrition.

Non-Technical Interpretation

  • Employees with 3 years at the company are likely to leave 15 (15.375) times more than those at 2 years.
  • Long-tenured employees (7-10 years) leave much less often with 0% ((0.000+0.000+0.000)/3)leaving.
Graph 4