22. Skim Text 4B “Experimentation as a Scienti fi c Research Method” and try to understand what it is about. Give a brief overview of its structure and contents.

Text 4B. Experimentation as a scientific method

 Experimentation is one scientific research method, perhaps the most recognizable, in a spectrum of methods that also includes description, comparison, and modelling. While all of these methods share in common a scientific approach, experimentation is unique in that it involves the conscious manipulation of certain aspects of a real system and the observation of the effects of that manipulation. You could solve a cell phone reception problem by walking around a neighbourhood until you see a cell phone tower, observing other cell phone users to see where those people who get the best reception are standing, or looking on the web for a map of cell phone signal coverage. All of these methods could also provide answers, but by moving around and testing reception yourself, you are experimenting.

In the experimental method, a condition or a parameter, generally referred to as a variable, is consciously manipulated (often referred to as a treatment) and the outcome or effect of that manipulation is observed on other variables. Variables are given different names depending on whether they are the ones manipulated or the ones observed: independent variable refers to a condition within an experiment that is manipulated by the scientist; dependent variable refers to an event or outcome of an experiment that might be affected by the manipulation of the independent variable. Scientific experimentation helps to determine the nature of the relationship between independent and dependent variables. While it is often difficult, or sometimes impossible, to manipulate a single variable in an experiment, scientists often work to minimize the number of variables being manipulated. For example, as we move from one location to another to get better cell reception, we likely change the orientation of our body, perhaps from south-facing to east-facing, or we hold the cell phone at a different angle. Which variable affected reception: location, orientation, or angle of the phone? It is critical that scientists understand which aspects of their experiment they are manipulating so that they can accurately determine the impacts of that ma nipulation. In order to constrain the possible outcomes of an experimental procedure, most scientific experiments use a system of controls.  

In a controlled study, a scientist essentially runs two (or more) parallel and simultaneous experiments: a treatment group, in which the effect of an experimental manipulation is observed on a dependent variable, and a control group, which uses all of the same conditions as the first with the exception of the actual treatment. Controls can fall into one of two groups: negative controls and positive controls. In a negative control, the control group is exposed to all of the experimental conditions except for the actual treatment. The need to match all experimental conditions exactly is so great that, for example, in a trial for a new drug, the negative control group will be given a pill or liquid that looks exactly like the drug, except that it will not contain the drug itself, a control often referred to as a placebo. Negative controls allow scientists to measure the natural variability of the dependent variable(s), provide a means of measuring error in the experiment, and also provide a baseline to measure against the experimental treatment.

 Some experimental designs also make use of positive controls. A positive control is run as a parallel experiment and involves the use of an alternative treatment that the researcher knows will have an effect on the dependent variable. For example, when testing the effectiveness of a new drug for pain relief, a scientist might administer treatment placebo to one group of patients as a negative control, and a known treatment like aspirin to a separate group of individuals as a positive control since the pain-relieving aspects of aspirin are well documented. In both cases, the controls allow scientists to quantify background variability and reject alternative hypotheses that might otherwise explain the effect of the treatment on the dependent variable.

Experiments are used across all scientifi c disciplines to investigate a multitude of questions. In some cases, scientifi c experiments are used for exploratory purposes in which the scientist does not know what the dependent variable is. In this type of experiment, the scientist will manipulate an independent variable and observe what the effect of the manipulation is in order to identify a dependent variable (or variables). Exploratory experiments are sometimes used in nutritional biology when scientists probe the function and purpose of dietary nutrients. In one approach, a scientist will expose one group of animals to a normal diet, and a second group to a similar diet except that it is lacking a specific vitamin or nutrient. The researcher will then observe the two groups to see what specific physiological changes or medical problems arise in the group lacking the nutrient being studied [Carpi, Egger, 2008]. 

23. Identify the topic of each paragraph of Text 4B.

24. Complete the sentences choosing the best variant corresponding to the contents of Text 4B.

 1) Experimentation is unique because it … a) includes description, comparison, and modelling. b) is a scientific research method. c) is the treatment of certain aspects of a real system.

2) A variable in the experimental method is … a) a condition or parameter. b) a treament of a condition or parameter. c) a manipulation of a condition or parameter.

3) The nature of the relationship between dependent and independent variables can be determined by … a) their manipulation. b) experimental methods. c) their observation.

 4) In a controlled study, a scientist usually perform … a) one experiment. b) two experiments. c) a few experiments at the same time.

 5) Experimental methods are used in … a) a certain number of scientifi c disciplines. b) all scientific disciplines. c) nutritional biology only.

Section 5. SPEAKING

25. Here are some useful tips/phrases that will help you to speak about the research methods applied. Study and learn these phrases.

My research employs multiple methods towards investigating the phenomena of …, including experimentation, description, comparison, and modelling.

My thesis involves the application of the methodology / methods of …

There are several methods of doing …

Modern methods of scientifi c analysis have been applied …

We have applied an alternative method which …

The methods of investigation I employ in my research include … in order to understand/determine …

A new approach to … is presented.

Different methods may be combined in a single study.

Many of these methods overlap or are used in combination.

These methods could also provide the answers to …

reliable methods of analysing the facts of …

This method is used to study …/ in a study of …

The comparative method is useful in …

We use an interdisciplinary approach to …

The methods of … used in the study allow/permit … to conduct experiments or make observations about …

This phenomenon… was examined by the … method.

These facts are compared with …

The system is studied by … method.

Experimental methods help to determine the nature of the relationship between … Description is used to gather data regarding … and includes observations and measurements of …

Comparison is used to determine/quantify …

26. Make up and act dialogues of your own considering the following assignments. Use the above expressions.

1. Your colleague asks you about the research methods you are using in your research. 2. The teacher conducts the English lesson and asks you some questions about the experimental method(s) applied in your research.

 27. Speak on the research methods you are using in your work. Use the above expressions and the dialogues made up as a model.