laboratory experiments

• In many of the natural sciences, such as p____ and c____, the laboratory experiment is the main means by which scientists do what 3 things?

• Similarly, positivist sociologists, who model their approach on what, may also occasionally use l______ experiments.

• However, sociologists often also use two other kinds of experiment in their research: field experiments, and the c____ m_____ or 't____ e____'.

• In many of the natural sciences, such as physics and chemistry, the laboratory experiment is the main means by which scientists gather data, test theories and discover scientific laws of cause and effect.

• Similarly, positivist sociologists, who model their approach to research on the logic and methods of the natural sciences, may also occasionally use laboratory experiments.

• However, sociologists often also use two other kinds of experiment in their research: field experiments, and the comparative method or 'thought experiment'.

Key features of laboratory experiments

What are 2 key features of laboratory experiments

1. control

2. cause and effect

Key features of laboratory experiments - Control

• A laboratory experiment is a controlled experiment- how?

• In this way, the scientist can test h____ about the c____ of a p____, with the aim of discovering a c____ l____.

Key features of laboratory experiments - Control

• A laboratory experiment is a controlled experiment- The laboratory is an artificial environment in which the scientist can control different variables in order to discover what effect they have.

• In this way, the scientist can test hypotheses about the cause of a phenomenon, with the aim of discovering a causal law.

Key features of laboratory experiments - Control

• In a laboratory experiment, the researcher first takes a set of s___ (things/participants). These must be i____ in all relevant respects.

They are then divided at random into two groups - what are these groups? The researcher then treats the two groups differently:

1. The e____ group are exposed to a v____ (called the i_____ v____) that the researcher believes may have a p____ e____.

2. The control group are not e_____ to the i____ v_____ - their conditions are kept c____.

Key features of laboratory experiments - Control

• In a laboratory experiment, the researcher first takes a set of subjects (things/participants). These must be identical in all relevant respects.

They are then divided at random into two groups - an experimental group and a control group. The researcher then treats the two groups differently:

1. The experimental group are exposed to a variable (called the independent variable) that the researcher believes may have a particular effect.

2. The control group are not exposed to the independent variable - their conditions are kept constant.

Key features of laboratory experiments - Cause and effect

• The condition of both groups is measured what 2 times?

• If we discover a change in the e_____ group but none in the c____ group, we may conclude that this was caused by what?

• In other words, by following the logic of the experimental method, we can discover what?

• This allows us to p____ what will happen under the same c___ in the future.

Key features of laboratory experiments - Cause and effect

• The condition of both groups is measured before the experiment starts and again at the end.

• If we discover a change in the experimental group but none in the control group, we may conclude that this was caused by the different treatments the two groups received.

• In other words, by following the logic of the experimental method, we can discover cause-and-effect relationships.

• This allows us to predict what will happen under the same conditions in the future.

• However, while laboratory experiments are the basic research method in most natural sciences, how often are they used in sociology?

• There are a number of p____, e_____ and t____ reasons for this.

• However, while laboratory experiments are the basic research method in most natural sciences, they are rarely used in sociology.

• There are a number of practical, ethical and theoretical reasons for this.

• what are the 6 practical issues of using laboratory experiments?

1. open systems 

2. individuals are too complex 

3. studying the past 

4. small samples 

5. the hawthorne effect  

practical issues of using laboratory experiments

• Sociologists such as K____ and U____ (1982) argue that laboratory experiments are only suitable for studying closed systems - why?

• However, society is an o_____ s____ where c_____ f____ are at work in any g___ s____, interacting with each other in c____ ways.

• This makes it impossible for the researcher to do what?

• This makes laboratory experiments unsuitable for studying what?

practical issues of using laboratory experiments

• Sociologists such as Keat and Urry (1982) argue that laboratory experiments are only suitable for studying closed systems where the researcher can control and measure all the relevant variables and make precise predictions, as in physics or chemistry.

• However, society is an open system where countless factors are at work in any given situation, interacting with each other in complex ways.

• This makes it impossible for the researcher even to identify, let alone control, all the relevant variables.

• This makes laboratory experiments unsuitable for studying social phenomena.

practical issues of using laboratory experiments - individuals are complex

• Individuals are complex and therefore it is not really possible to do what ?

• While we can find i_____ s___ of c____, no two human beings are e____ a____.

practical issues of using laboratory experiments - individuals are complex

• Individuals are complex and therefore it is not really possible to 'match' the members of the control and experimental groups exactly.

• While we can find identical samples of chemicals, no two human beings are exactly alike.

practical issues of using laboratory experiments - Studying the past

• Laboratory experiments cannot be used to study what? and why?

• Nor can we keep people in laboratory conditions for l____ t____ p____ so we can study them.

practical issues of using laboratory experiments - Studying the past

• Laboratory experiments cannot be used to study an event in the past, since we cannot control variables that were acting in the past rather than the present.

• Nor can we keep people in laboratory conditions for long time periods so we can study them.

practical issues of using laboratory experiments - small samples 

• Laboratory experiments can usually only study s____ s_____.

• This makes it very difficult to investigate l____-s____ s___ p____.

• For example, we cannot study all or even a l____ s____ of the members of a m____ r____.

• Small samples also bring what risk?

practical issues of using laboratory experiments - small samples 

• Laboratory experiments can usually only study small samples.

• This makes it very difficult to investigate large-scale social phenomena.

• For example, we cannot study all or even a large sample of the members of a major religion.

• Small samples also bring the risk that a result that appears to show one variable causing another, may in fact just be a chance correlation between the two.

practical issues of using laboratory experiments - The Hawthorne Effect

• A laboratory experiment is an a_____ environment and any behaviour that occurs in it may also be a_____.

• In particular, if the subjects know they are being experimented on, how might this make them act/feel?

• The Hawthorne effect originates from where?

• This shows that in laboratory experiments participants may a____ their behaviour due to awareness of being s____ rather than the e____ v____, reducing v___.

• This 's____ r____' will a____ the experiment, since it depends on the subjects responding to the what? and not reacting to what?

practical issues of using laboratory experiments - The Hawthorne Effect

• A laboratory experiment is an artificial environment and any behaviour that occurs in it may also be artificial.

• In particular, if the subjects know they are being experimented on, this may make them act differently. e.g they may feel ,anxious about being in the experiment and act differently as a result.

• The Hawthorne effect originates from studies at the Hawthorne factory in the USA (1920s), where researchers found that workers’ productivity increased simply because they knew they were being observed, regardless of changes in working conditions.

• This shows that in laboratory experiments participants may alter their behaviour due to awareness of being studied rather than the experimental variables, reducing validity.

• This 'subject reactivity' will affect the experiment, since it depends on the subjects responding to the variables that the researcher introduces into the situation, and not reacting to the fact that they are being studied.

practical issues of using laboratory experiments - The expectancy effect

• The expectancy effect is a form of what bias? and wha5 does it refer to?

• This can occur by the experimenter c____ or u_____ treating the subjects in such a way that it i_____ how they r_____ and p____ the result the experimenter e___

practical issues of using laboratory experiments - The expectancy effect

• The expectancy effect is a form of experimenter bias- it refers to the fact that what a researcher expects to happen in the experiment can affect its actual outcome.

• This can occur by the experimenter consciously or unconsciously treating the subjects in such a way that it influences how they respond and produces the result the experimenter expected

what are the 3 ethical issues of using laboratory experiments?

• informed consent

• harm to subjects

• potential benefitors

ethical issues of using laboratory experiments →informed consent

• Researchers are to gain a______ to take part, having first e____ to them in t____ they can u_____, the n_____ and p____ of the experiment, what risks and effects there may be, and the uses to which the findings will be put.

• However, sometimes explaining the aim of the experiment beforehand will be s____-d____. In these cases, for the experiment to work, what was happen and why?

ethical issues of using laboratory experiments →informed consent

• Researchers are to gain agreement to take part, having first explained to them in terms they can understand, the nature and purpose of the experiment, what risks and effects there may be, and the uses to which the findings will be put.

• However, sometimes explaining the aim of the experiment beforehand will be self-defeating. In these cases, for the experiment to work, the subjects must be deceived because, if they know its true purpose, they may very well act differently.

ethical issues of using laboratory experiments →Harm to subjects

• Research should not normally harm the participants.

• However, what do some researchers argue ?

ethical issues of using laboratory experiments →Harm to subjects

• Research should not normally harm the participants.

• However, some argue that minor or temporary harm may be justified ethically if the results yield significant social benefits.

ethical issues of using laboratory experiments → potential benefactors

• Research should also seek to do g____.

• However, a problem arises when laboratory experiments are conducted primarily for f_____ g____, rather than to genuinely help participants.

• For example, p____ or commercial research may b____ the c_____ or r__ f____, while participants receive little or no long-term benefit.

• This raises ethical concerns - why?

ethical issues of using laboratory experiments → potential benefactors

• Research should also seek to do good.

• However, a problem arises when laboratory experiments are conducted primarily for financial gain, rather than to genuinely help participants.

• For example, pharmaceutical or commercial research may benefit the company or researchers financially, while participants receive little or no long-term benefit.

• This raises ethical concerns because participants may be treated as tools to achieve research objectives rather than being treated with respect and consideration.

Theoretical issues of using laboratory experiments

• For positivists, laboratory experiments have a major theoretical strength - their r_____.

• However, in other respects they suffer from important limitations even from a positivist perspective.

• Interpretivists go even further, criticising laboratory experiments how?

Theoretical issues of using laboratory experiments

• For positivists, laboratory experiments have a major theoretical strength - their reliability.

• However, in other respects they suffer from important limitations even from a positivist perspective.

• Interpretivists go even further, criticising laboratory experiments as lacking validity and as unsuitable for studying actors' meanings.

Theoretical issues of using laboratory experiments →Reliability and hypothesis testing (positivist argument)

• what is a reliable method?

• why do Positivists see reliability as important ?

• If we can r____ the research and arrive at the same r_____, we can have more c______ that the o____ f______ are true.

Theoretical advantages of using laboratory experiments →Reliability and hypothesis testing (positivist argument)

• A reliable method is one that can be replicated - repeated exactly in every detail by other researchers to obtain the same results.

• Positivists see reliability as important because it enables us to check the work of other researchers by repeating it.

• If we can repeat the research and arrive at the same results, we can have more confidence that the original findings are true.

Theoretical advantages of using laboratory experiments →Reliability and hypothesis testing (positivist argument)

Positivists regard the laboratory experiment as highly reliable for three reasons- what are these reasons?

Theoretical advantages of using laboratory experiments →Reliability and hypothesis testing (positivist argument)

Positivists regard the laboratory experiment as highly reliable for three reasons:

1. The original experimenter can control the conditions and specify the precise steps that were followed in the original experiment, so others can easily repeat these steps to re-run it.

2. It produces quantitative data, so the results of the re-run experiments can be easily compared to the original.

3. It is a very detached and objective method: the researcher merely manipulates the variables and records the results. Their subjective feelings and values have no effect on the conduct or outcome of the experiment.

Theoretical advantages of using laboratory experiments →Reliability and hypothesis testing (positivist argument)

• Because laboratory experiments can i_____ and c_____ any variable that is of i____ to the researcher, they are also an effective way to test h____ and p____.

• If we believe a particular v____ is the cause of a p_____, we simply set up an experiment where an experimental group is exposed to that variable and a control group is not, and then c___55 the outcomes.

Theoretical advantages of using laboratory experiments →Reliability and hypothesis testing (positivist argument)

• Because laboratory experiments can isolate and control any variable that is of interest to the researcher, they are also an effective way to test hypotheses and predictions.

• If we believe a particular variable is the cause of a phenomenon, we simply set up an experiment where an experimental group is exposed to that variable and a control group is not, and then compare the outcomes.

Theoretical issues of using laboratory experiments →Representativeness

• For positivists, representativeness is important - why?

• However, with laboratory experiments there is a danger that their findings lack external validity→ what does this mean?

There are two reasons for this:

1. Firstly, because experiments can only study s____ samples, there is a greater risk that they are not a r______ c____-s_____ of the population the researcher is interested in. If so, the findings cannot be g____ beyond the experiment itself

2. Secondly, lack of external validity arises out of the high level of c___ the experimenter has. Control over the conditions in the experiment is valuable, how? On the other hand, however, the higher the level of control we have over the experiment, the more u_____ the circumstances this creates - which may not be at all true of the world outside the l____.

Theoretical issues of using laboratory experiments →Representativeness

• For positivists, representativeness is important because they aim to make generalisations about how the wider social structure shapes individuals behaviour.

• However, with laboratory experiments there is a danger that their findings lack external validity→ we cannot be confident they are true for the wider population.

There are two reasons for this:

1. Firstly, because experiments can only study small samples, there is a greater risk that they are not a representative cross-section of the population the researcher is interested in. If so, the findings cannot be generalised beyond the experiment itself

2. Secondly, lack of external validity arises out of the high level of control the experimenter has. Control over the conditions in the experiment is valuable, because it enables us to establish that a particular variable causes a particular effect. On the other hand, however, the higher the level of control we have over the experiment, the more unnatural the circumstances this creates - which may not be at all true of the world outside the laboratory.

Theoretical issues of using laboratory experiments →Internal validity

• Laboratory experiments may also lack internal validity→ what does this mean?

• One reason for this is the a_____ of the laboratory environment.

• As we saw earlier, this may encourage what?

Theoretical issues of using laboratory experiments →Internal validity

• Laboratory experiments may also lack internal validity→ That is, their findings may not even be true for the subjects of the experiment itself, let alone the wider world

• One reason for this is the artificiality of the laboratory environment.

• As we saw earlier, this may encourage the Hawthorne effect, where the subjects react simply to being studied, and do so in ways that produce invalid results

Theoretical issues of using laboratory experiments →Interpretivism and free will

• Interpretivists argue that human beings are fundamentally different from what? and why?

• Our behaviour is not ‘caused' by e_____ forces, so it cannot be explained in terms of c_____-and-e____ s____, as positivists believe

• Instead, our actions can only be understood how?

• For interpretivists, therefore, the laboratory experiment, with its search for causes, is a fundamentally i______ method for studying human beings.

Theoretical issues of using laboratory experiments →Interpretivism and free will

• Interpretivists argue that human beings are fundamentally different from plants, rocks and other natural phenomena that natural scientists study - unlike these objects, we have free will and choice.

• Our behaviour is not ‘caused' by external forces, so it cannot be explained in terms of cause-and-effect statements, as positivists believe

• Instead, our actions can only be understood in terms of the choices we freely make on the basis of the meanings we give to events.

• For interpretivists, therefore, the laboratory experiment, with its search for causes, is a fundamentally inappropriate method for studying human beings.