The input field "Xi" is confusing to all new users, because its name carries no information about what it means or how to set it.
I suggest changing it to "Desired further improvement", because that is the most condensated form of what the value means. In addition, you could give the field a hover-text that reads: "Desired improvement measured from your best data point."
If it is possible to add a little information bubble with a more verbose explanation, that could have the following text:
Desired improvement in relation to the best result obtained thus far. Use the same scale as your scores and update this value as you gather more data. Large values result in suggestions far away from previously tried settings, small values result in suggestions close to the expected minimum of the model. As an example, if your best result is 100 and you wish to reach 25, this value should be set to 75.
The input field "Xi" is confusing to all new users, because its name carries no information about what it means or how to set it.
I suggest changing it to "Desired further improvement", because that is the most condensated form of what the value means. In addition, you could give the field a hover-text that reads: "Desired improvement measured from your best data point."
If it is possible to add a little information bubble with a more verbose explanation, that could have the following text: Desired improvement in relation to the best result obtained thus far. Use the same scale as your scores and update this value as you gather more data. Large values result in suggestions far away from previously tried settings, small values result in suggestions close to the expected minimum of the model. As an example, if your best result is 100 and you wish to reach 25, this value should be set to 75.