Notes

Principles, Theories, and Hypotheses:

A principle is a rule or a law that relates to a factual aspect of a phenomenon seen in the natural environment. Principles are established and proven norms regarding a concept, and they apply to specific situations. For instance, Newton’s laws of motion pertain to the relationship between a body and the use of force.
A hypothesis is a prediction or assumption about the outcome of an experiment based on prior knowledge. For instance, in the context of psychological studies, there could be a hypothesis that the knowledge of having to work through the weekend will make an individual feel frustrated from the beginning of the week itself. The observation of individuals under such circumstances can help support or rebut the hypothesis. Therefore, a hypothesis needs to undergo certain tests, and the resulting evidence may or may not support the hypothesis and prove it correct.
A theory results from a proven hypothesis or hypotheses supported by multiple tests, experiments, observations, and evidence. Theories come into existence when a specific hypothesis consistently holds true under certain circumstances. The hypothesis needs to show the same results repeatedly for a theory to be universally accepted. Theories may, however, be proven wrong with the help of new evidence. Similarly, theories might change or evolve through the application of the latest knowledge, experiments, and so on.
The development of a psychological theory is a lengthy process. The scientific methoda systematic process that focuses on obtaining information through logical reasoning, confirming facts, and investigating conceptsplays a pivotal role in the development of psychological theories. This method includes four major steps: hypothesis formation, data collection, data examination, and reporting.
Hypothesis formation: At this step, researchers make a prediction based on information that they already possess. Prior knowledge forms the basis of a hypothesis, which in turn forms the foundation of a theory. Observation of any of the myriad aspects of psychology can lead to the formation of a hypothesis. For instance, a researcher can focus on the relationship between two aspects, such as student preparation and anxiety associated with an upcoming test. Based on this observation, a researcher can create the hypothesis that “better preparation helps combat anxiety related to examinations.”
Data collection: At this step, a researcher uses one or more of the available research methods to collect the information required to support or disprove the hypothesis.
Data examination: The third step involves examining and analyzing the data or evidence. The researcher scrutinizes the information, confirms the results, and uses statistical concepts to represent the collected data. Statistics can support the conclusion of the study since it supports the reliability and credibility of the research as well as the results. Based on this analysis, the researcher can determine whether the hypothesis is true or false or requires further evaluation.
Reporting: The last step is reporting or publishing the results of the study. The researcher needs to ensure that the information regarding the hypothesis, methods of research used, data analysis, information about research participants, outcome of certain experiments, etc., are included in the report. Researchers from other fields can analyze such information, conduct independent studies, and determine if it is possible to replicate or refute the results.
Theory is a proven hypothesis supported by experimental evidence. Hypothesis is a prediction about the outcome of an experiment based on prior knowledge. Principle is a rule or law relating to a natural phenomenon
Sociological research or social scientific reasoning plays a major role in the development of psychological theories. The basis of such research is a set of established research models and methods. Three of the most commonly used sociological research models or designs are the cross-sectional model, longitudinal model, and crosssequential model.
Cross sectional model: The cross-sectional model studies a group of individuals belonging to different age groups, but who have a common set of problems, symptoms, traits, etc., at a given point of time. For instance, a research study may focus on a group of 20 individuals suffering from stress, with each participant from a distinct age group and having a unique source of stress.
Longitudinal model: The longitudinal model refers to the study of a particular individual, group, society, or community over a predetermined period, which may be a specified number of weeks, months, or years.
Crosssequential model: The crosssequential model involves the study of individuals from different age groups, similar to the crosssectional model. However, this model studies its participants more than one time during a specified period.
Case studies: In case studies, researchers analyze the behavioral patterns, emotional imbalances, or other psychological aspects of a group or an individual. Such research generally takes place in a clinic, where the researcher observes the subject or group over several months or even a year. During this period, the researcher collects the necessary information pertaining to the hypothesis. Research in case studies mostly relates to a group of people who have similar psychological characteristics, such as depression, anxiety, etc. This research method does not apply to a generic or random group of people, but to specific traits. A drawback of case studies is that a biased researcher can influence the reactions and opinions of the participants.
Surveys: Surveys involve the use of questionnaires or interviews that probe a selected group of individuals, or the sample, on a particular psychological topic. Questionnaires may ask respondents about their choices in a given scenario, about specific experiences, or about how they handled a particular situation in the past. The questionnaires might ask a respondent to answer questions with a yes or no, tick whether statements are true or false, rate personal characteristics on a scale of 1 to 10, and so on. Apart from the use of questionnaires, a researcher may choose to interview all the individuals in a group and note down their responses to various questions. Using the Internet, a researcher can also email a questionnaire to many respondents at once.
Surveys also have their share of drawbacks.A researcher might display prejudiced behavior during personal interviews, which in turn might affect the answers given by the respondents. Apart from interviewer bias, there is also a possibility of volunteer bias. For instance, certain volunteers or respondents might already have inflexible notions or beliefs about a particular subject. In such cases, the sample or selected group does not fairly represent the entire population. There might also be cases of distortion, wherein certain respondents choose to give dishonest answers.
Observational research: This type of research, also known as non-participant observation, is a solution to the problem of distorted responses seen in case of surveys. As the term suggests, the researcher simply observes the respondents without interfering in the process. Such observation helps the researcher gauge a respondent’s genuine reaction to a question, the level of seriousness that a respondent shows with respect to the study, and the respondent’s interest in the subject. This research method encourages respondents to be more open instead of feeling nervous or embarrassed.
Psychologists can conduct observational research in one of two environments: a laboratory or a natural environment. However, it’s important to remember that laboratory observation and naturalistic observation are prone to volunteer bias and dishonesty. In addition, participants might display opposite behaviors in a natural setting and in a laboratory.
Experiments: This research method involves investigating a phenomenon. In an experiment, a researcher changes a particular aspect of a situation, called a variable, and examines whether the change affects a second variable that is under observation.
Experimental success depends on various factors. First, the randomly selected sample should fairly represent the population; otherwise, the researcher cannot claim that the results of the study are valid. Secondly, if the researcher has any type of experimenter bias concerning the subject, this can adversely affect the outcome of the experiment. Lastly, the researcher needs to control extraneous variables or external factors that can affect the experiment’s reliability. For example, factors such as noise can hinder the quality of an ongoing experiment and eventually affect its conclusion.
Cross-cultural research: Religious, social, cultural, and political views that are prevalent in a society will influence the behaviors and attitudes of people in the society. Cross-cultural research involves studying a diverse group of individuals using surveys and observational research. It uses a method called participant observation.
The researcher participates in the study and joins the respondents, or subjects who are part of the study. Thus, the researcher is able to interact with people from varied backgrounds, communities, and age groups, and to collect information about them. This type of study helps a researcher understand how cultural and social norms differ in different societies. Cross-cultural research also reveals practices, etiquettes, and behavioral patterns that are unique to a particular community, but which face rejection from other communities or religious groups.
Correlational research: This type of research involves establishing a relationship between two different aspects or variables in a given situation. In the context of psychology, variables can include emotions, feelings, behaviors, attitudes, beliefs, empathy, and so on. Correlational research uses methods such as observational research, personal interviews, surveys, and case studies to find the extent of the connection between two variables. Correlations can be of three types: positive, negative, and non-existent. A positive correlation between two variables suggests that a change will affect both variables, meaning that the values of both variables will either increase or decrease together. A negative correlation between two variables implies that a change will result in an increase in the value of one variable and a decrease in the value of the other variable. A nonexistent correlation refers to the absence of a relationship between two variables.
Secondary analysis: If it is difficult to collect new data, a researcher can use information that governments, businesses, and educational institutions have already made available for public use on websites or in libraries, and other records. Secondary analysis refers to the use of data obtained from secondary sources to form a hypothesis and develop a theory.

Qualitative Versus Quantitative Research:
Psychologists use two basic types of research methods to develop theories: qualitative research and quantitative research.
Qualitative research: An example of a qualitative research method is a case study, which involves a researcher obtaining and analyzing qualitative data such as the behaviors and experiences of the participants. The researcher cannot quantify the information obtained, which means it cannot be expressed in numerical or statistical terms. The data is in the form of thoughts, ideas, or experiences shared by the respondents during the study. Similarly, data gathered through a survey is qualitative if the questions posed in the survey are subjective and not restricted by controlled responses such as yes/no.
Quantitative research: In quantitative research, researcher can express the results in terms of a quantity or number. Research methods such as experiments, surveys with closed-ended questions, and laboratory observations focus on obtaining statistical data. Researchers can then carry out statistical analysis of the data in the form of graphs, tables, and so on.
he longitudinal model is a study of an individual, group, society, or community over a predetermined period. The cross-sequential model is a recurring study of individuals from different age groups over a specific period. The cross-sectional model is a study of a group of individuals who are from different age groups, but who share certain characteristics.
Statistics
Statistics are of immense importance in psychological studies. In quantitative research studies, statistics can help researchers to organize and describe data and to draw conclusions based on the data.
Organizing data: Psychological studies involve a huge amount of data. Researchers use statistical tools such as graphs and charts to organize and interpret information obtained through research.
Describing data: Statistics help researchers describe data in accurate numerical terms. For example, a research study may state that 20percent of smokers complain about work-related stress.
Drawing conclusions: Based on statistical representation of the data collected in a study, a researcher can arrive at a conclusion that either proves or disproves the given hypothesis.
Population: In statistical terms, a population refers to a group or community that forms the basis of the research. In the context of psychological studies, the population consists of all the people who are included in a study.
Sample: A sample is a small unit of members that researchers select from among the population for evaluation. The sample represents the population. Thus, any conclusions that apply to the sample are applicable to the population as well. Sampling refers to the procedure for selecting members from the population. A researcher will then question or interview the chosen members using a particular research method in order to obtain information that supports or refutes the hypothesis.
Statistic: A statistic is a value that a researcher derives from a sample. For example, the average value of the responses of a given sample is a statistic of the sample. Statistics associated with a sample include the mean, mode, and median, which you will study later in this lesson.
Parameter: A parameter is the same as a statistic, except that it applies to the entire population of a study and not just to the sample.
Variable: A variable is an aspect or component of a study that can undergo changes or variations. Examples of variables include time, accuracy, quantity, and so on.
Independent variable: In psychological studies, an independent variable refers to an aspect of a study that a researcher can change, influence, or manipulate. Consider the hypothesis that performing yoga every morning helps sales managers to reduce work-related stress. In a research study to confirm this hypothesis, the practice of yoga is the independent variable because the researcher can change it between respondents.
Dependent variable: The dependent variable is an aspect of a study that varies due to a change in the independent variable. In our previous example, the level of stress that sales managers experience is the dependent variable. The researcher’s basic assumption is that a change in the value of the independent variable will result in a change in the value of the dependent variable.
Random selection: Random selection refers to the way in which a researcher chooses members from the population. As the term suggests, the selection process is random; that is, it does not follow a specific pattern. For example, a researcher may randomly draw 200 names from a population of 1,000 people.
Random assignment: Random assignment follows the process of selecting a sample. It involves dividing the chosen sample into treatment and control groups. The treatment group refers to a group that undergoes certain experiments or changes during the study. In contrast, the individuals in a control group are not part of any such treatments. In our previous example, suppose the researcher randomly selects 200 sales managers from a population of 1,000 managers. Out of the whole sample, the researcher may instruct a treatment group of 100 managers to practice yoga every morning, while requesting the remaining 100 managers to continue with their current daily routines. In this scenario, random assignment helps the researcher to evaluate the effect that the experiment has on the treatment group in comparison to the control group.
In psychological studies, researchers may use random selection, random assignment, both these techniques, or neither technique.
Probability sampling: In this method of sampling, a researcher selects the members of a sample based on probability or chance. Random sampling is an example of probability sampling. In the case of large populations, a researcher may use a computer program to create a random list of people. The crux of probability sampling is that each member of the population has an equal and fair chance of being part of the sample. It ensures that the sample is representative of the entire population.
Non-probability sampling: In contrast to probability sampling, non-probability sampling refers to not selecting a sample randomly. In some studies, it is not possible for the researcher to contact or access information from the entire population. Time constraints also limit a researcher’s method of selecting a sample. In such cases, researchers select a group from the population based on their own judgment or on the willingness of people to be part of a sample. In this sampling method, a large portion of the population does not have a fair chance of being part of the sample. For this reason, non-probability sampling does not fairly represent the actual population and may give rise to a sampling error.