ERROR IN THE CONCLUSION 3
Error in the Conclusion
The conclusion is that there is linear correlation between the numberof cigarettes smoked and pulse rate. By definition, the linearcorrelation used is statistical based on measurement made ofcausation, direction, the significance of the two variables(cigarette smoking and pulse rate) and degree. The conclusion thatincreased cigarette smoking leads to increased pulse rates is wrongsince linear correlations only tell us about the strength ofrelationship between variables (Shadish, Cook and Campbell, 2006).Ideally, a correlation that is linear does not explain the causalrelationship in this case. For instance, it is almost impossible totell the cause-effect relationship. To this end, correlation in thiscase does not tell the causal relationship that exists between thetwo variables.
Correlation only explains the phenomena of one variable increasingand resulting in the increase of ‘effects’ on the other variable.To this end, increased cigarette smoking is just an ‘accelerator’of pulse rate rather than the ‘cause’ and this is where the errorlies. In cases where a causal relationship exists one variableincreases as result of the increase in the other variable ‘as aneffect’ (Shadish, Cook and Campbell, 2006). For instance, in aconclusion that states that ‘physical inactivity leads to obesity’is a linear correlation between variables but with one variable beingan effect. In this case, we can say for certain that increasedphysical inactivity increases chances of obesity.
The conclusion that increased cigarette smoking leads to increasedpulse rate, we cannot assertively state which variable is the causesince there is a linear correlation between variables. In this case,an increase in one variable leads to an increase in the othervariable. To elaborate further, assume there is linear correlationbetween height and weight. It is hard to tell that height increase ordecrease means an increase or decrease in weight. As such, the linearconclusion that increased cigarette smoking leads to increased pulserate is erroneous. It is hard to tell which variable causes the other(Shadish, Cook and Campbell, 2006).
Shadish, W. Cook, T. D. Campbell, D. T. (2006). Experimental andquasi-experimental designs for generalized causal inference.Houghton Mifflin.