# Inter experiment conditions

When designing experiments, especially in psychological and behavioral research, between-group designs are commonplace. These designs involve comparing two or more groups, with each group experiencing a different condition. [Cognition](https://www.cognition.run/) has integrated tools to efficiently manage these inter-experiment conditions. Let's delve into how you can utilize this feature:

#### **1. The Essence of Between-Group Study Design**

In between-group (or between-groups) designs, different participants are assigned to different conditions, ensuring that each group experiences only one of the conditions.

#### **2. Automatic Participant Assignment**

Cognition streamlines the condition assignment process by:

* Automatically allocating participants to different conditions.
* If you specify multiple conditions, Cognition will ensure an even distribution of participants across these conditions. This balance ensures unbiased results and easier statistical analysis.

#### **3. Accessing Assigned Condition in Runtime**

Once a participant is assigned to a condition, this information is made available during the experiment runtime via the variable `CONDITION`.

#### **4. Practical Application**

Let's explore a practical code example to understand how `CONDITION` can be harnessed:

```javascript
var test_stimuli = [
    { stimulus: "img/blue.png", correct_response: CONDITION == 2 ? 'f' : 'j' },
    { stimulus: "img/orange.png", correct_response: CONDITION == 2 ? 'j' : 'f' }
];
```

In this scenario:

* If a participant has been assigned to Condition 2, their correct responses will be 'f' for the blue image and 'j' for the orange image.
* For participants in any other condition, the correct responses are reversed.

#### **5. Testing Specific Conditions**

While editing your task and using the live preview function:

* Cognition provides an option titled "Set condition."
* This tool allows you to simulate a specific condition, ensuring you can test the task as if you were a participant assigned to that condition.

**6. Set Specific Condition Using URL Query Parameters**

In addition to the automatic condition assignment feature, Cognition offers flexibility in allowing researchers to set specific conditions using URL query parameters. By appending the query parameter `condition` to the experiment URL, researchers can bypass the auto-balancing algorithm and ensure that a participant sees a specific version of the experiment.

For example, if you append `?condition=2` to the experiment URL, the participant will be assigned to Condition 2 regardless of the auto-balancing logic. This feature is particularly useful for researchers who wish to control the version seen by specific participants, allowing for more targeted experimentation.

**7. Pros of Using Conditions vs. Creating Multiple Tasks**

When designing experiments with between-group study designs, researchers often face the decision of whether to use conditions within a single task or create multiple tasks. Each approach has its own set of advantages and disadvantages:

**Pros of Using Conditions:**

* **Single Unique URL:** With conditions, researchers only need to manage a single unique URL for the experiment, simplifying participant recruitment and sharing.
* **Auto-Balancing:** Cognition's auto-balancing system ensures an even distribution of participants across conditions, leading to more reliable and unbiased results.
* **Easy Maintenance:** Managing a single task with conditions is more straightforward and requires less maintenance compared to managing multiple tasks.

In conclusion, the inter-experiment conditions feature in Cognition greatly simplifies the process of managing and implementing between-group study designs. Whether you're comparing two conditions or several, Cognition ensures a balanced and efficient distribution of participants, all while giving you the tools to easily craft and test condition-specific task elements.