Getting started

Launching an experiment to crowdsourcing participants requires following this process:

  1. Visiting http://[url]:8421/init with the [url] from Installation.

  2. Creating a username/password

  3. Launching an experiment.

  4. Sending the URL http://[url]:8421/ to crowdsourcing participants.

Initialization page

By default, Salmon does not support HTTPS. Make sure the URL begins with http://, not https://. For example, the URL you visit may look like:


When visiting http://[url]:8421/init, first, type a username/password and hit “create user.”


Do not lose this username/password! You need the username/password to view the dashboard and download the received responses.

It is technically possible to recover the username/password with the key file key.pem that Amazon AWS provides and the URL above:

(personal) $ ssh -i key.pem ubuntu@[url]
(ec2) $ cat /home/ubuntu/salmon/creds.json

Experiment initialization

Hit the back button to visit http://[url]:8421/init again after after a user has been successfully created. Now, let’s launch an experiment! There are three options:

  1. Upload of a YAML file completely detailing the experiment.

  2. Upload of a YAML file describing experiment, and ZIP file for the targets.

  3. Upload of a database dump from Salmon.

These options are detailed at “Experiment initialization.” If an experiment is incorrectly specified, (hopefully helpful) errors will be raised. After the experiment is finished launching, you will see a couple links:

  • A link to the dashboard (http://[url]:8421/dashboard), an example of which is at “Experiment monitoring.”

  • A link to the query page to send to crowdsourcing users (http://[url]:8421/).

Send the URL to participants

The URL to send to the crowdsourcing participants is http://[url]:8421/. Typically, paid services like Mechantical Turk are used to recruit crowdsourcing participants. Reddit and email have been used for unpaid recruitment. In either case, that may involve a URL of this form:

Opening this URL in the browser will show (a newer version) of this page:


A couple notes: