efficaciness

November 21, 2006 11:20 AM

Is there a significant or important difference, in any professional or disciplinary vocabulary or within any academic discourse, between the words 'efficacy' and 'effectiveness'?
posted by milkman to writing & language (15 comments total)

No important difference that I'm aware of, with the obvious point that different words give people different impressions about you, depending on context. Sometimes people will think you're smart if you use "efficacy" instead of "effectiveness", other times they'll will assume you're a pompous windbag. It's nice to have both words.

It's the same business with "utililize" and "use".
posted by Hildago at 11:27 AM on November 21, 2006

They are basically synonymous, although efficacy seems to be the preferred term when discussing drugs and other medical treatments. Most likely this is because of the distinction, when evaluating medical treatments, between activity and efficacy. For example, a compound may be active against a microbe, but not efficacious in curing the disease. Effective can mean active in this context, so efficacy is used to specify that the treatment achieves its ultimate goal (control or cure), rather than just succeeds at an intermediate step.
posted by j-dawg at 11:30 AM on November 21, 2006

According to the OED, efficacy and efficacious have been in use longer than effectiveness and that "efficacious" is "Said of instruments, methods, or actions; not, in prose, of personal agents" and efficacy is "Not used as an attribute of personal agents." Bryan Garner has a long entry on this in his Dictionary of Modern American Usage ("Thus, efficacy exists when you can do something at all while efficiency exists when you con do something quickly and well.)
posted by mattbucher at 11:37 AM on November 21, 2006

Of course it depends on context, but there can be a distinction akin to a distinction between general and specific actions. Bruce Wampold uses the words this way in The Great Psychotherapy Debate to differentiate between the results of studies which show us that psychotherapy works, and those that claim to show us that specific therapies work (are effective) in specific ways.

From pp.60-61 in his book:

It is not time to explain the distinction [between the words]...Efficacy refers to the benefits of psychotherapy that are derived from comparisons of the treatment and no-treatment control in the context of a well-controlled clinical trial. That is, if a treatment is found to be superior to a waiting-list control group in a treatment package design, then the treatment is said to be efficacious. Effectiveness, on the other hand, refers to the benefits of psychotherapy that occur in the practice context--that is, how effective are the treatments administered to clients who present to therapists in the community?...the establishment of the efficacy of psychotherapy does not ipso facto imply that the treatments are beneficial to clients (i.e., are effective).

Wampold is a PhD psychologist and a statistician.
posted by OmieWise at 11:38 AM on November 21, 2006 [1 favorite has favorites]

One more thought: It's also worth noting that "effective" has several other definitions, whereas efficacious really only has one. While it's hard to imagine many instances in which one of these other definitions for effective might crop up in context, some probably exist. So, for that reason, efficacy may also be more precise.
posted by j-dawg at 11:38 AM on November 21, 2006

In philosophy, "causal efficacy" is a pseudo-technical idiom. "Causal effectiveness" would sound weird, or at least non-standard. Some philosophers (e.g. Frank Jackson and Philip Pettit) argue that there is a difference between casual efficacy and causal relevance; using a term like "causal effectiveness" might blur the two.
posted by painquale at 11:50 AM on November 21, 2006

In political science, efficacy is a term of art for a set of related attitudes that a person holds about their place in the political system. Someone with high efficacy believes that the government is responsive to their interests, that they can understand political issues, and so on. Effectiveness is just itself; it's not a term of art.
posted by ROU_Xenophobe at 11:52 AM on November 21, 2006

ROU: You're suggesting that a political subject's efficacy in these terms is entirely constructed by his or her perception? It is a psychological and entirely self-reflective category?
posted by milkman at 12:09 PM on November 21, 2006

No, I'm informing you that the term "political efficacy" is a term of art meaning only those internal, psychological attitudes. I'm not making any suggestion about actual facts on the ground, only telling you how a term is used and what meaning it carries.
posted by ROU_Xenophobe at 12:45 PM on November 21, 2006

I'm sorry if I wasn't clear. I understand that we are not talking about 'actual facts on the ground'. My original question was not about how efficacy is determined.

As a term of art, within the political science discourse you are describing, am I correct in understanding that 'efficacy' describes a category of institutional effectiveness as understood by the subject his or herself ? As in, if I were discussing your 'political efficacy', I would be describing the way you see yourself?

This is an honest query. I have some background in political science, and I am not familiar with this specific distinction.
posted by milkman at 1:07 PM on November 21, 2006

I think that's correct. I don't do behavior myself and can't recall the exact questions, but you measure political efficacy (at least for Americans) with a more-or-less standardized set of survey questions about different attitudes.

I think it would be possible to be wrongly high-efficacy if you can't understand politics as well as you think you can, but there may be political-knowledge questions in the standard index that I'm not remembering.
posted by ROU_Xenophobe at 1:58 PM on November 21, 2006

Regarding political efficacy, this definition I found online seems to most closely correspond to what I believed the term meant:

The extent to which people feel they have an impact or exert some influence on public affairs.

It applies to a person (or a demographical group), and not to the institution, and for the most part, it does not seem to be used in a sense that refereces any specific institution or governmental aspect, but refers to government-at-large.

linky
posted by Maxwell_Smart at 2:42 PM on November 21, 2006

Good old Wikipedia captures the difference between the words as I use them in a health care setting:
"The word effective is sometimes used in a quantitative way, "being very or not much effective". However it does not inform on the direction (positive or negative) and the comparison to a standard of the given effect. Efficacy, on the other hand, is the ability to produce a desired amount of the desired effect, or success in achieving a given goal. Contrary to efficiency, the focus of efficacy is the achievement as such, not the resources spent in achieving the desired effect. Therefore, what is effective is not necessarily efficacious, and what is efficacious is not necessarily efficient."
posted by rmhsinc at 3:33 PM on November 21, 2006

I do biomedical research and would always use efficacy over effectiveness when describing drug action or other bioactive compounds. We scientists shun ambiguity and efficacy is a more precise term with a specific meaning in this context (as already nicely described by j-dawg above). Using terms other than the preferred one is generally considered unacceptable (scientists can be somewhat boring also) and if I used effectiveness in a peice of 'proper' writing I'd expect it to be edited out or changed.

So yes, there is an important difference within the biomedical sciences between the words 'efficacy' and 'effectiveness'.
posted by shelleycat at 7:15 PM on November 21, 2006

I'd use Fowler's old but still reliable Modern English Usage as the arbiter in this one, which discusses the difference in the adjectival forms thus: "efficacious only applies to things (especially now to medicine) used for a pupose and means sure to have, or usually having, the desired effect . . .effective applies to the thing done or its doer as such, and means having a high degree of effect"
posted by Neiltupper at 7:26 AM on November 22, 2006