A basic stat’s question and a specific PSPP query, please. Any help gratefully received. I can’t see this in the archives anywhere (searching for ‘categorical’ and ‘dummy’).
For a linear regression, some variables are categorical and so included using dummy coding (Coding Systems for Categorical Variables in Regression Analysis (ucla.edu)).
basic stat’s question: This results in a zero coefficient and zero standard error for some variables, as shown in the example below. Is this correct? There is little or no linear relationship to be found?
specific PSPP query: if there is little relationship/the coefficient is very small, is there a way to tell PSPP to show the very small value instead of zero?
Thanks in advance
Table: Model Summary (adjRA1SR1) | | | | | |
R | R Square | Adjusted R Square | Std. Error of the Estimate | | | |
0.55723 | 0.310505 | 0.302797 | 0.8359 | | | | |
| | | | | | | |
Table: ANOVA (adjRA1SR1) | | | | | |
| Sum of Squares | df | Mean Square | F | Sig. | | |
Regression | 619.25791 | 22 | 28.148087 | 40.284698 | 0 | | |
Residual | 1375.0987 | 1968 | 0.698729 | | | | |
Total | 1994.3566 | 1990 | | | | | |
| | | | | | | |
Table: Coefficients (adjRA1SR1) | | | | | |
| Unstandardized Coefficients | Standardized Coefficients | t | Sig. | 95% Confidence Interval for B |
| B | Std. Error | Beta | | | Lower Bound | Upper Bound |
(Constant) | 8.163407 | 0.310014 | 0 | 26.332394 | 0 | 7.555417 | 8.771397 |
lnSTINC | -0.036745 | 0.011677 | -0.088107 | -3.146888 | 0.002 | -0.059645 | -0.013845 |
RA1PKHSIZ | -0.011834 | 0.016218 | -0.020561 | -0.729708 | 0.466 | -0.043639 | 0.019971 |
RA1PRAGE | -0.039326 | 0.011175 | -0.550388 | -3.519082 | 0 | -0.061242 | -0.01741 |
sqPRAGE | 0.000464 | 0.000109 | 0.666977 | 4.258349 | 0 | 0.00025 | 0.000678 |
RA1PRSEX | 0.13709 | 0.03935 | 0.068446 | 3.483888 | 0.001 | 0.059918 | 0.214261 |
RA1PB19_1 | 0 | 0 | 0 | NaN | NaN | 0 | 0 |
RA1PB19_2 | -0.485628 | 0.170694 | -0.054029 | -2.845015 | 0.004 | -0.820389 | -0.150867 |
RA1PB19_3 | -0.324574 | 0.058981 | -0.109094 | -5.503011 | 0 | -0.440246 | -0.208902 |
RA1PB19_4 | -0.333625 | 0.089807 | -0.074169 | -3.714896 | 0 | -0.509752 | -0.157497 |
RA1PB1 | -0.002888 | 0.008407 | -0.007002 | -0.343559 | 0.731 | -0.019376 | 0.0136 |
RA1SG17A_1 | 0 | 0 | 0 | NaN | NaN | 0 | 0 |
RA1SG17A_2 | -0.061221 | 0.053837 | -0.021822 | -1.137147 | 0.256 | -0.166804 | 0.044363 |
RA1PA1 | -0.15082 | 0.022182 | -0.160102 | -6.7991 | 0 | -0.194324 | -0.107317 |
RA1PA2 | -0.248882 | 0.024367 | -0.243609 | -10.214077 | 0 | -0.29667 | -0.201095 |
RA1SC1 | -0.328042 | 0.073134 | -0.08782 | -4.485512 | 0 | -0.471469 | -0.184614 |
RA1PF3bin | 0.003064 | 0.041159 | 0.001422 | 0.074435 | 0.941 | -0.077655 | 0.083783 |
RA1PF7A_2 | 0.009538 | 0.086914 | 0.002111 | 0.109735 | 0.913 | -0.160917 | 0.179992 |
RA1PF7A_3 | 0.14177 | 0.166844 | 0.016081 | 0.849712 | 0.396 | -0.18544 | 0.468979 |
RA1PF7A_4 | -0.104009 | 0.155971 | -0.01266 | -0.666848 | 0.505 | -0.409894 | 0.201877 |
RA1PF7A_5 | 0.173309 | 0.59246 | 0.005486 | 0.292525 | 0.77 | -0.988606 | 1.335224 |
RA1PF7A_6 | 0.064264 | 0.080864 | 0.01504 | 0.794712 | 0.427 | -0.094325 | 0.222853 |
RA1PG2 | -0.350528 | 0.030049 | -0.233421 | -11.66509 | 0 | -0.40946 | -0.291597 |