What are some potential pitfalls when using PHP for communication between clients in a web-based experiment?

One potential pitfall when using PHP for communication between clients in a web-based experiment is the lack of real-time updates due to the stateless nature of HTTP. To address this issue, you can implement long polling or websockets to achieve real-time communication between clients.

// Example of using long polling in PHP for real-time communication between clients
// Client-side code
<script>
    function longPolling() {
        $.ajax({
            url: 'polling.php',
            success: function(data) {
                // Handle the response data
                // Call longPolling() again to continue polling
                longPolling();
            }
        });
    }

    longPolling();
</script>

// Server-side code (polling.php)
<?php
// Perform any necessary data processing
// Echo the response data
echo $responseData;
?>