Here is an example of an unfocused summary and a brief discussion of how the writer wanders off point. A much more focused summary follows.
Original Source:
Better Farming Methods: Organic farming of animals and field crops is cleaner. "Conventional farmers have no regulations regarding management of manure. Organic does," says Fred Kirschenmann, Ph.D., director of the Leopold Center for Sustainable Agriculture at Iowa State University. "You have to leave at least 90 days-120 days for root crops-between application of manure and the harvest. That's how long it takes for bacteria such as E. coli to degrade and become neutralized in the soil." Kirschenmann, who was a member of the National Organic Standards Board, expresses regret that the final rules don't require that ruminant animals be "pasture-based" to ensure that they get out and graze. In practice, though, "all the organic meat producers I know of are small, two to three hundred head, and they all graze, get exercise, eat organic foods-just before slaughter they are switched to corn, which is usually grown on the farm," says Scowcroft. If a cow gets sick and is treated with antibiotics, it cannot be labeled "organic." Wihelm says she would welcome an organic hog farm as a neighbor. Consumers can also seek ecological, humanely raised meat from local farms, or look for other sustainable labels.
--Excerpted from Mindy Pennybacker, "Why Fast Food Costs Too Much"
Unfocused Summary:
In her Green Guide article, "Why Fast Food Costs Too Much" Mindy Pennybacker argues that applying organic methods when raising field crops and animals makes for cleaner farming practices. Citing Fred Kirschenmann, director of the Leopold Center for Sustainable Agriculture at Iowa State University and a member of the National Organic Standards Board, she points out that E. coli bacteria requires 90-120 days between manure application and the actual harvest to be rendered harmless. Since organic farmers must abide by regulations established by the National Organic Standards Board to be certified as organic, manure application to their crop fields is carefully monitored. Conventional farmers have no such oversight. Completely unmonitored, manure gets applied to their crops in ways that are hazardous to the environment. In turn, this creates ideal conditions in which E. coli, Salmonella and other infectious bacteria thrive and enter the food chain.
While this summary is accurate, it includes points that do little to help the reader understand the main focus. The fact that organic farming is cleaner than conventional farming is not really the point, nor the fact that a 90-120 day cycle is required for E. coli to be rendered completely harmless.
The main point is that, unlike organic farms, manure management on conventional farms is completely unregulated which creates a dangerously unhealthy environment in which to raise farm crops and animals.
Extra details clutter up this summary, creating additional distractions the reader must wade through while trying to grasp its main focus. The fact that Fred Kirschenmann directs the Leopold Center for Sustainable Agriculture at Iowa State University and is a member of the National Organic Standards Board is a case in point. It's extremely wordy and completely irrelevant.
Now, suppose the "90-120 day" detail in the summary was necessary. Should Fred Kirschenmann be cited? Not necessarily. Information of this sort quite often falls into the category of widely-accepted. Check a variety of resources. If you can find such information readily, it is not privately-held intellectual property and authorship need not be cited.
The following revision eliminates unnecessary details and is much more sharply focused on the main idea. Again, notice how much shorter the summary is.
Focused Summary:
In her Green Guide article, "Why Fast Food Costs Too Much" Mindy Pennybacker argues that, since organic farmers must abide by regulations established by the National Organic Standards Board to be certified as organic, manure application to their crop fields is carefully monitored. No other farmers have such oversight. As a result, manure is applied to conventional crops in ways that are hazardous to the environment, creating ideal conditions in which E. coli, Salmonella and other infectious bacteria thrive and enter the food chain.