## Google Sheets IMPORTRANGE: Looking up data with the VLOOKUP function

Note! This is part of a series on using IMPORTRANGE in Google Sheets. If you don’t know how to use IMPORTRANGE or what it is, I encourage you to head back to the first tutorial.

When I first sat down to write this tutorial, I had a specific opinion that one approach to using VLOOKUP on IMPORTRANGE data was better than another. However, I wanted to be certain. I ran some basic tests comparing the two approaches to see how they both perform over large data sets, and you know what? I was surprised to find I couldn’t find a discernable difference in performance.

Next, I reached out to some of the other fellow Google Sheets nerds, who like to go way too far with software for all the wrong reasons, and they seemed to feel that those demi-gods of Google devs really understand the wayward predilections of their users and may have benevolently stored the IMPORTRANGE data locally in the sheet you have imported to.

Will we ever know for certain? Only ever perhaps in the lay of the tea leaves or roll of the bones. We can but only guess the ways of the Googler as they traverse the digital world in all their etheral glory.

What does this mean in short? There are two pretty solid ways to use VLOOKUP with IMPORTRANGE. I’ll cover both in this tutorial.

## How to compare current week’s data with previous week’s data in Google Sheets

Google Sheets: WEEKNUM, WEEKDAY, FILTER, VLOOKUP, TODAY

One really helpful metric to check performance is to compare the current weeks worth of data against the previous weeks. I have had need of this in all sorts of projects such as:

• Comparing sales performance from previous weeks to current.
• Comparing hours worked on different tasks from week to week.
• Compare the assessment balance between weekly tests.
• Compare attendance numbers.

The problem is you often only receive data in to form of a date, like 1 Nov 2020. We will go through one possible solution to this problem in this tutorial.

We’ll run through an example together that you should be able to quickly adapt to your own project.

Let’s get cracking!