Variables are crucial part of one eye tracking experiment. A variable is anything that can change or it is in changed. In various other words, it is any kind of factor that have the right to be manipulated, regulated for, or measure up in one experiment.Experiments save different species of variables. We will existing you with several of the main types of speculative variables, their definitions and also give you examples containing every variable types.

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Types of speculative variables:

Independent variables (IV): These space the determinants or conditions that girlfriend manipulate in one experiment. Your theory is the this variable causes a direct effect on the dependent variable.Dependent variables (DV): These room the factor that you watch or measure. Together you vary your independent change you watch what happens to her dependent variable.
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Extraneous variable: an extraneous varable is any type of extra aspect that may influence the outcome of one experiment, even though that is not the focus of the experiment. Ideally, this variables won’t influence the conclusions attracted from the results as a careful experimental design should equally spread out influence throughout your check conditions and also stimuli.Nevertheless, extraneous variables should always be considered and also controlled when feasible as lock may present unwanted sports in your data. In this case, you have to tweak your design and also procedure to be able to keep the variation constant or uncover a strategy to monitor its affect (constant or controlled variables).All experiments have actually extraneous variables. Right here are some instances of different types of extraneous variables:aspects that the environment where the data collection will take place, e.g., room temperature, elevator noise level, irradiate levels;differences in participant qualities (participant variables); andtest operator, or experimenter habits during the test, i.e., your instructions come the check participants are not continual or they give unintentional hints of the score of the experiment to the participants.
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Figure 2. Screens the impact of extraneous variables ~ above the relationship in between the independent and dependent variables.


managed (or constant) variables: space extraneous variables that you regulate to keep continuous or managed for during the food of the experiment, together they may have an effect on your dependent variables as well.Participant variables: Participant variables can be characterized as the differing individual characteristics that may impact how a participant responds in an experiment. Examples of participant variables encompass gender, age, ethnicity, socioeconomic status, proficiency status, mood, clinical diagnosis etc.Stimulus variables: these are certain features of her stimulus or group of stimuli the are component of the paper definition in which the habits occurs. This are regularly an expression that or a subset of her independent variables and covariates. Examples encompass the variety of items, items category, stimulus crowdedness, color, brightness, contrast, etc.

Operationalizing variables

Before you start your experiment, you require to have a clear definition of, and also strategy for, just how each variable will be measured and also recorded. This procedure is referred to as variable operationalization.

For example, you room interested in studying perspectives towards food, intuitive attention, and also food choice. In your very first study, her objective is to inspection “the effect of an individual health objectives on visual fist to various food groups”.

The first part of her objective, “the result of an individual health goals…”, includes an live independence variable. Come operationalize the you need to ask yourself the following questions: What is a an individual health goal? have the right to you quantify and measure it? deserve to you rest it under into distinct categories? exactly how will girlfriend collect and also record that is value? because of the nature the this term, her variable will most likely be written of two or much more categories (e.g. Shed weight, save weight, get weight etc.) and its value recorded by method of a questionnaire or interview. Notice that in this example, the independent variable is also an intrinsic attribute that a participant and thus specific to that individual, together a result, this variable can additionally be classified together a participant variable.

The next part of your study objective “…on visual attention to various food groups”, consists of your dependent variable. Once again, friend will need to ask you yourself the complying with questions: What is intuitive attention? how do ns measure it? exactly how is food grouped? how will we represent the different groups in the stimuli? Which group strategy is pertinent to my objective? The term “visual fist to” deserve to be operationalized into one or much more relevant visual actions measures that can be quantified and measured continuously. For example, eye tracking metrics favor fixation duration, permanent count, and dwell time can provide you through information about the intuitive engagement and bias towards various items in her stimulus. The “… different food groups” term will most most likely be operationalized as food varieties aggregated into categories (e.g. Vegetables, red meat, dairy) and displayed on photo stimulus. Due to the fact that you are manipulating the content of the stimulus and also the manipulation affect the context in which the actions occurs as well as the viewing behavior itself, her stimulus categories will certainly be part of your set of live independence variables and also simultaneously a stimulus variable.


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Figure 3. Reflects one possible outcome the the operationalization that the various variables in the example study. The objective of this study is to uncover out what effect personal health goals have on a person"s visual attention to various food groups.

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In the example above, the participant’s "current hunger state" is a element that may impact visual behavior and attention bias. If a check participant ate their enjoy the meal a lengthy time back and feels hungry, their fist may become focused ~ above high calorie food groups, also though they can normally no look come those food items as soon as they"re satisfied. If you decision to neglect it, it i do not care an extraneous change in her experiment and also may affect the relationship between your independent and also dependent variable. Top top the various other hand, if you decide to attend to it and also control because that it, girlfriend will additionally have come operationalize it, e.g. You have the right to measure it as the elapsed time due to the fact that the critical meal. If you then ask every your research participants to eat a meal within 1 hour before your test, this variable becomes a controlled variable, as you shot to standardize the level that hunger throughout your independent variable groups.